merge revision(s) b1c73f239fe9af97de837331849f55d67c27561e,bb570ce6d80d28cfc7131dcb72885eed2f989b30,b88d1e6b44164bca0c2b85ea6639469813e1e1d8,127f735c1e5e0771076caf2a74390757a42fb177,f3f1a666c77f8c528b0adc9ccf78e4b9910bd6e0,fa048a0f8523cefde5428805dd334691486319e6,d5d1c41728d65acfb8aa2cf95f2d8ac88f271cd1,52ebaf718e6a78297ceb0dff49815eeed28eae45,7fe22152fc28084f4395fece84ff6e5eb2d6b288,19e6d271266eca5925e66fc8ec39b251a2fa6bcd,05898c5b9001c0b1e8bd7bf0d12b42a8e7c388b8,3651f678a719ae3a35825bcb4e0dabbc7c60d8df,10b082064e6ab0943cce4ef43e567d8044c7096d,de8e6218a3257fe19b46ff0aa157e66f452ac8b7,971a0cd246db6578e1ea8760a903e1a23e3681f3,61a29a41e1d0d11a9963315aa86d25ed690124c0,ff9a00887161840eb8a34d53749a7d7962181cfe,fad3412d475b57055f426cf4e86eafeab516672b,54aa11efa8b1be2c5d20402890d6d2fa90aa19a8,e84d275fe6d0c14ba58ce73b13323879c060b7ae,61e1cf23ac0d122fba3ad4cbaa402c7c94ad54d3,a6948329f8f89fb390215086fe4a888915fd589e,64b991b0cd98ee8f23266b8cbea0fa34bdaab1ec,b1c73f239fe9af97de837331849f55d67c27561e,0ee24b4fab1a1faef600a42c29863e1c3edd8c61: [Backport #17877]

Synchronize rdoc with upstream version v6.3.1.

	[ruby/rdoc] Use File.open to fix the OS Command Injection
	 vulnerability in CVE-2021-31799

	https://github.com/ruby/rdoc/commit/a7f5d6ab88
	---
	 lib/rdoc/rdoc.rb            |  2 +-
	 test/rdoc/test_rdoc_rdoc.rb | 12 ++++++++++++
	 2 files changed, 13 insertions(+), 1 deletion(-)

	[ruby/rdoc] Support ChangeLog generated by `git log`

	https://github.com/ruby/rdoc/commit/5e0a123ca1
	---
	 lib/rdoc/parser/changelog.rb            | 35 +++++++++++++++++++++
	 test/rdoc/test_rdoc_parser_changelog.rb | 56 +++++++++++++++++++++++++++++++++
	 2 files changed, 91 insertions(+)

	[ruby/rdoc] Make each commit entries h3

	https://github.com/ruby/rdoc/commit/11eefb2ae9
	---
	 lib/rdoc/parser/changelog.rb            | 12 ++++++------
	 test/rdoc/test_rdoc_parser_changelog.rb | 12 ++++--------
	 2 files changed, 10 insertions(+), 14 deletions(-)

	[ruby/rdoc] Tweak log entry markdown

	* add 3 levels to headings
	* prefix commit log to labels to make unique IDs

	https://github.com/ruby/rdoc/commit/5074c13209
	---
	 lib/rdoc/parser/changelog.rb            | 20 +++++++++++++++++-
	 test/rdoc/test_rdoc_parser_changelog.rb | 36 ++++++++++++++++++++++++++++++++-
	 2 files changed, 54 insertions(+), 2 deletions(-)

	[ruby/rdoc] Shorten commit hashes

	https://github.com/ruby/rdoc/commit/5d3e153963
	---
	 lib/rdoc/parser/changelog.rb            | 2 +-
	 test/rdoc/test_rdoc_parser_changelog.rb | 2 +-
	 2 files changed, 2 insertions(+), 2 deletions(-)

	[ruby/rdoc] Add links to the commits

	https://github.com/ruby/rdoc/commit/1821628076
	---
	 lib/rdoc/parser/changelog.rb            | 107 +++++++++++++++++++++++++-------
	 test/rdoc/test_rdoc_parser_changelog.rb |  36 ++++++-----
	 2 files changed, 107 insertions(+), 36 deletions(-)

	[ruby/rdoc] Sort by CommitDate if available

	https://github.com/ruby/rdoc/commit/455715e930
	---
	 lib/rdoc/parser/changelog.rb            | 11 ++++++---
	 test/rdoc/test_rdoc_parser_changelog.rb | 40 +++++++++++++++++++++++++++++++++
	 2 files changed, 48 insertions(+), 3 deletions(-)

	[ruby/rdoc] Skip non-date logs by git-log

	`RDoc::Parser::ChangeLog` mis-parses ChangeLog generated by
	git-log, because of too heuristic `Time.parse`.

	For instance, "commit 8187228de0142d3ac7950b7d977c2849e934c637"
	results in "8187-08-16", that is, day 228 in the year 8187.

	https://github.com/ruby/rdoc/commit/9711e6f6d9
	---
	 lib/rdoc/parser/changelog.rb            | 36 ++++++++++++++++++++-------------
	 test/rdoc/test_rdoc_parser_changelog.rb |  2 ++
	 2 files changed, 24 insertions(+), 14 deletions(-)

	[ruby/rdoc] Support other date formats in git-log

	https://github.com/ruby/rdoc/commit/ad8cf37d72
	---
	 lib/rdoc/parser/changelog.rb            |  6 +++---
	 test/rdoc/test_rdoc_parser_changelog.rb | 22 ++++++++++++++++++++++
	 2 files changed, 25 insertions(+), 3 deletions(-)

	[ruby/rdoc] Support iso-strict format in git-log

	https://github.com/ruby/rdoc/commit/2a6c22da63
	---
	 lib/rdoc/parser/changelog.rb            |  6 +++---
	 test/rdoc/test_rdoc_parser_changelog.rb | 11 +++++++++++
	 2 files changed, 14 insertions(+), 3 deletions(-)

	[ruby/rdoc] Update Rdoc.css sidebar panel.

	Updates css so the sidebar look like a panel instead of looking like chopped edges.

	https://github.com/ruby/rdoc/commit/b0098c6d72
	---
	 lib/rdoc/generator/template/darkfish/css/rdoc.css | 1 +
	 1 file changed, 1 insertion(+)

	[ruby/rdoc] Support GFM table

	https://github.com/ruby/rdoc/commit/9dc933df16
	---
	 lib/rdoc/markdown.rb                    | 349 +++++++++++++++++++++++++++++++-
	 lib/rdoc/markup.rb                      |   1 +
	 lib/rdoc/markup/table.rb                |  47 +++++
	 lib/rdoc/markup/to_html.rb              |  23 +++
	 lib/rdoc/markup/to_joined_paragraph.rb  |   1 +
	 lib/rdoc/markup/to_rdoc.rb              |  28 +++
	 lib/rdoc/markup/to_table_of_contents.rb |   1 +
	 test/rdoc/test_rdoc_markdown.rb         |  23 +++
	 8 files changed, 471 insertions(+), 2 deletions(-)
	 create mode 100644 lib/rdoc/markup/table.rb

	[ruby/rdoc] Add table style

	https://github.com/ruby/rdoc/commit/2219c5ae80
	---
	 lib/rdoc/generator/template/darkfish/css/rdoc.css | 19 +++++++++++++++++++
	 1 file changed, 19 insertions(+)

	[ruby/rdoc] Fixed CodeFence without blank lines

	Currently a fenced code block needs a preceding blank line, it
	should not be required, as:
	https://github.github.com/gfm/#fenced-code-blocks
	> A fenced code block may interrupt a paragraph, and does not
	> require a blank line either before or after.

	Just recommended:
	https://docs.github.com/en/github/writing-on-github/creating-and-highlighting-code-blocks
	> We recommend placing a blank line before and after code blocks
	> to make the raw formatting easier to read.

	https://github.com/ruby/rdoc/commit/0e1776caf3
	---
	 lib/rdoc/markdown.rb            | 447 +++++++---------------------------------
	 test/rdoc/test_rdoc_markdown.rb |  36 +++-
	 2 files changed, 112 insertions(+), 371 deletions(-)

	[ruby/rdoc] Allow partial default values to be overridden with
	 .rdoc_options

	https://github.com/ruby/rdoc/commit/e14800891f
	---
	 lib/rdoc/options.rb         | 34 +++++++++++++++++++++++++++++++++-
	 lib/rdoc/rdoc.rb            |  7 ++++++-
	 test/rdoc/test_rdoc_rdoc.rb | 12 ++++++++++++
	 3 files changed, 51 insertions(+), 2 deletions(-)

	[ruby/rdoc] Allow empty .rdoc_options

	https://github.com/ruby/rdoc/commit/0c8cb25b50
	---
	 lib/rdoc/rdoc.rb            |  2 ++
	 test/rdoc/test_rdoc_rdoc.rb | 11 +++++++++++
	 2 files changed, 13 insertions(+)

	[ruby/rdoc] Suppress unused variable warning of "text"

	https://github.com/ruby/rdoc/commit/3a4120b155
	---
	 lib/rdoc/markdown.rb | 345 ++++++++++++++++++++++++++++++++++++++++++++++++++-
	 1 file changed, 343 insertions(+), 2 deletions(-)

	[ruby/rdoc] Get rid of a trailing space

	https://github.com/ruby/rdoc/commit/7b7b91768e
	---
	 lib/rdoc/markdown.rb | 7 +++----
	 1 file changed, 3 insertions(+), 4 deletions(-)

	[ruby/rdoc] Disable other notations in <code> tags

	https://github.com/ruby/rdoc/commit/0cd3b55210
	---
	 lib/rdoc/markup/attr_span.rb                    |  10 ++-
	 lib/rdoc/markup/attribute_manager.rb            | 102 ++++++++++++++++++------
	 test/rdoc/test_rdoc_markup_attribute_manager.rb |  24 +++++-
	 test/rdoc/test_rdoc_markup_to_html.rb           |   6 ++
	 4 files changed, 114 insertions(+), 28 deletions(-)

	[ruby/rdoc] Treat other tags as word boundaries

	https://github.com/ruby/rdoc/commit/8222f85a17
	---
	 lib/rdoc/markup/attribute_manager.rb  | 17 +++++++++++++----
	 test/rdoc/test_rdoc_markup_to_html.rb |  5 +++++
	 2 files changed, 18 insertions(+), 4 deletions(-)

	[ruby/rdoc] Treat emphasis tags as excluding other notations

	And exclusive notations don't exclude other exclusive notations.

	https://github.com/ruby/rdoc/commit/b8baa9a435
	---
	 lib/rdoc/markup/attr_span.rb                    |  2 +-
	 lib/rdoc/markup/attribute_manager.rb            | 10 +++++-----
	 test/rdoc/test_rdoc_markup_attribute_manager.rb |  1 +
	 3 files changed, 7 insertions(+), 6 deletions(-)

	[ruby/rdoc] Clarify that dots in URL are replaced

	The dots in all path components from the document root are
	replaced with underscores, not only in the basename.

	https://github.com/ruby/rdoc/commit/7a3417ea4c
	---
	 test/rdoc/test_rdoc_top_level.rb | 3 +++
	 1 file changed, 3 insertions(+)

	[ruby/rdoc] Links to document texts without "rdoc-ref:" prefix

	While links to generated HTML from RDoc file needs to be prefixed
	by "rdoc-ref:" currently, in case of explicit references this
	seems just redundant.

	Also GitHub RDoc support does not work with this prefix.

	This patch lets links to such document texts (".rb", ".rdoc" and
	".md" now) refer URLs generated by `RDoc::TopLevel#http_url`
	without the prefix.

	https://github.com/ruby/rdoc/commit/f18b27b69d
	---
	 lib/rdoc/markup/to_html.rb            |  4 ++++
	 test/rdoc/test_rdoc_markup_to_html.rb | 21 +++++++++++++++++++++
	 2 files changed, 25 insertions(+)

	[ruby/rdoc] Use File.open to fix the OS Command Injection
	 vulnerability in CVE-2021-31799

	https://github.com/ruby/rdoc/commit/a7f5d6ab88
	---
	 lib/rdoc/rdoc.rb            |  2 +-
	 test/rdoc/test_rdoc_rdoc.rb | 12 ++++++++++++
	 2 files changed, 13 insertions(+), 1 deletion(-)

	[ruby/rdoc] Version 6.3.1

	https://github.com/ruby/rdoc/commit/9307f932b7
	---
	 lib/rdoc/version.rb | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)

14 files changed, 834 insertions, 70 deletions

diff --git a/lib/rdoc/generator/template/darkfish/css/rdoc.css b/lib/rdoc/generator/template/darkfish/css/rdoc.css
index 35aff77fcb..ebe2e93af6 100644
--- a/lib/rdoc/generator/template/darkfish/css/rdoc.css
+++ b/lib/rdoc/generator/template/darkfish/css/rdoc.css
@@ -79,6 +79,25 @@ pre {
   border-radius: 0.2em;
 }
 
+table {
+  margin: 0;
+  border-spacing: 0;
+  border-collapse: collapse;
+}
+
+table tr th, table tr td {
+  padding: 0.2em 0.4em;
+  border: 1px solid #ccc;
+}
+
+table tr th {
+  background-color: #eceaed;
+}
+
+table tr:nth-child(even) td {
+  background-color: #f5f4f6;
+}
+
 /* @group Generic Classes */
 
 .initially-hidden {
@@ -166,6 +185,7 @@ nav {
   width: 260px;
   font-family: Helvetica, sans-serif;
   font-size: 14px;
+  border-right: 1px solid #ccc;
 }
 
 main {
diff --git a/lib/rdoc/markdown.rb b/lib/rdoc/markdown.rb
index 903e744105..15beaefcca 100644
--- a/lib/rdoc/markdown.rb
+++ b/lib/rdoc/markdown.rb
@@ -897,7 +897,7 @@ class RDoc::Markdown
     return _tmp
   end
 
-  # Block = @BlankLine* (BlockQuote | Verbatim | CodeFence | Note | Reference | HorizontalRule | Heading | OrderedList | BulletList | DefinitionList | HtmlBlock | StyleBlock | Para | Plain)
+  # Block = @BlankLine* (BlockQuote | Verbatim | CodeFence | Table | Note | Reference | HorizontalRule | Heading | OrderedList | BulletList | DefinitionList | HtmlBlock | StyleBlock | Para | Plain)
   def _Block
 
     _save = self.pos
@@ -923,6 +923,9 @@ class RDoc::Markdown
         _tmp = apply(:_CodeFence)
         break if _tmp
         self.pos = _save2
+        _tmp = apply(:_Table)
+        break if _tmp
+        self.pos = _save2
         _tmp = apply(:_Note)
         break if _tmp
         self.pos = _save2
@@ -9320,7 +9323,7 @@ class RDoc::Markdown
     return _tmp
   end
 
-  # Inlines = (!@Endline Inline:i { i } | @Endline:c &Inline { c })+:chunks @Endline? { chunks }
+  # Inlines = (!@Endline Inline:i { i } | @Endline:c !(&{ github? } Ticks3 /[^`\n]*$/) &Inline { c })+:chunks @Endline? { chunks }
   def _Inlines
 
     _save = self.pos
@@ -9367,12 +9370,41 @@ class RDoc::Markdown
             break
           end
           _save6 = self.pos
-          _tmp = apply(:_Inline)
+
+          _save7 = self.pos
+          while true # sequence
+            _save8 = self.pos
+            _tmp = begin;  github? ; end
+            self.pos = _save8
+            unless _tmp
+              self.pos = _save7
+              break
+            end
+            _tmp = apply(:_Ticks3)
+            unless _tmp
+              self.pos = _save7
+              break
+            end
+            _tmp = scan(/\A(?-mix:[^`\n]*$)/)
+            unless _tmp
+              self.pos = _save7
+            end
+            break
+          end # end sequence
+
+          _tmp = _tmp ? nil : true
           self.pos = _save6
           unless _tmp
             self.pos = _save5
             break
           end
+          _save9 = self.pos
+          _tmp = apply(:_Inline)
+          self.pos = _save9
+          unless _tmp
+            self.pos = _save5
+            break
+          end
           @result = begin;  c ; end
           _tmp = true
           unless _tmp
@@ -9390,61 +9422,90 @@ class RDoc::Markdown
         _ary << @result
         while true
 
-          _save7 = self.pos
+          _save10 = self.pos
           while true # choice
 
-            _save8 = self.pos
+            _save11 = self.pos
             while true # sequence
-              _save9 = self.pos
+              _save12 = self.pos
               _tmp = _Endline()
               _tmp = _tmp ? nil : true
-              self.pos = _save9
+              self.pos = _save12
               unless _tmp
-                self.pos = _save8
+                self.pos = _save11
                 break
               end
               _tmp = apply(:_Inline)
               i = @result
               unless _tmp
-                self.pos = _save8
+                self.pos = _save11
                 break
               end
               @result = begin;  i ; end
               _tmp = true
               unless _tmp
-                self.pos = _save8
+                self.pos = _save11
               end
               break
             end # end sequence
 
             break if _tmp
-            self.pos = _save7
+            self.pos = _save10
 
-            _save10 = self.pos
+            _save13 = self.pos
             while true # sequence
               _tmp = _Endline()
               c = @result
               unless _tmp
-                self.pos = _save10
+                self.pos = _save13
                 break
               end
-              _save11 = self.pos
+              _save14 = self.pos
+
+              _save15 = self.pos
+              while true # sequence
+                _save16 = self.pos
+                _tmp = begin;  github? ; end
+                self.pos = _save16
+                unless _tmp
+                  self.pos = _save15
+                  break
+                end
+                _tmp = apply(:_Ticks3)
+                unless _tmp
+                  self.pos = _save15
+                  break
+                end
+                _tmp = scan(/\A(?-mix:[^`\n]*$)/)
+                unless _tmp
+                  self.pos = _save15
+                end
+                break
+              end # end sequence
+
+              _tmp = _tmp ? nil : true
+              self.pos = _save14
+              unless _tmp
+                self.pos = _save13
+                break
+              end
+              _save17 = self.pos
               _tmp = apply(:_Inline)
-              self.pos = _save11
+              self.pos = _save17
               unless _tmp
-                self.pos = _save10
+                self.pos = _save13
                 break
               end
               @result = begin;  c ; end
               _tmp = true
               unless _tmp
-                self.pos = _save10
+                self.pos = _save13
               end
               break
             end # end sequence
 
             break if _tmp
-            self.pos = _save7
+            self.pos = _save10
             break
           end # end choice
 
@@ -9461,11 +9522,11 @@ class RDoc::Markdown
         self.pos = _save
         break
       end
-      _save12 = self.pos
+      _save18 = self.pos
       _tmp = _Endline()
       unless _tmp
         _tmp = true
-        self.pos = _save12
+        self.pos = _save18
       end
       unless _tmp
         self.pos = _save
@@ -15847,6 +15908,338 @@ class RDoc::Markdown
     return _tmp
   end
 
+  # Table = &{ github? } TableRow:header TableLine:line TableRow+:body { table = RDoc::Markup::Table.new(header, line, body) }
+  def _Table
+
+    _save = self.pos
+    while true # sequence
+      _save1 = self.pos
+      _tmp = begin;  github? ; end
+      self.pos = _save1
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _tmp = apply(:_TableRow)
+      header = @result
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _tmp = apply(:_TableLine)
+      line = @result
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _save2 = self.pos
+      _ary = []
+      _tmp = apply(:_TableRow)
+      if _tmp
+        _ary << @result
+        while true
+          _tmp = apply(:_TableRow)
+          _ary << @result if _tmp
+          break unless _tmp
+        end
+        _tmp = true
+        @result = _ary
+      else
+        self.pos = _save2
+      end
+      body = @result
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      @result = begin;  table = RDoc::Markup::Table.new(header, line, body) ; end
+      _tmp = true
+      unless _tmp
+        self.pos = _save
+      end
+      break
+    end # end sequence
+
+    set_failed_rule :_Table unless _tmp
+    return _tmp
+  end
+
+  # TableRow = TableItem+:row "|" @Newline { row }
+  def _TableRow
+
+    _save = self.pos
+    while true # sequence
+      _save1 = self.pos
+      _ary = []
+      _tmp = apply(:_TableItem)
+      if _tmp
+        _ary << @result
+        while true
+          _tmp = apply(:_TableItem)
+          _ary << @result if _tmp
+          break unless _tmp
+        end
+        _tmp = true
+        @result = _ary
+      else
+        self.pos = _save1
+      end
+      row = @result
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _tmp = match_string("|")
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _tmp = _Newline()
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      @result = begin;  row ; end
+      _tmp = true
+      unless _tmp
+        self.pos = _save
+      end
+      break
+    end # end sequence
+
+    set_failed_rule :_TableRow unless _tmp
+    return _tmp
+  end
+
+  # TableItem = "|" < (!"|" !@Newline .)+ > { text.strip }
+  def _TableItem
+
+    _save = self.pos
+    while true # sequence
+      _tmp = match_string("|")
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _text_start = self.pos
+      _save1 = self.pos
+
+      _save2 = self.pos
+      while true # sequence
+        _save3 = self.pos
+        _tmp = match_string("|")
+        _tmp = _tmp ? nil : true
+        self.pos = _save3
+        unless _tmp
+          self.pos = _save2
+          break
+        end
+        _save4 = self.pos
+        _tmp = _Newline()
+        _tmp = _tmp ? nil : true
+        self.pos = _save4
+        unless _tmp
+          self.pos = _save2
+          break
+        end
+        _tmp = get_byte
+        unless _tmp
+          self.pos = _save2
+        end
+        break
+      end # end sequence
+
+      if _tmp
+        while true
+
+          _save5 = self.pos
+          while true # sequence
+            _save6 = self.pos
+            _tmp = match_string("|")
+            _tmp = _tmp ? nil : true
+            self.pos = _save6
+            unless _tmp
+              self.pos = _save5
+              break
+            end
+            _save7 = self.pos
+            _tmp = _Newline()
+            _tmp = _tmp ? nil : true
+            self.pos = _save7
+            unless _tmp
+              self.pos = _save5
+              break
+            end
+            _tmp = get_byte
+            unless _tmp
+              self.pos = _save5
+            end
+            break
+          end # end sequence
+
+          break unless _tmp
+        end
+        _tmp = true
+      else
+        self.pos = _save1
+      end
+      if _tmp
+        text = get_text(_text_start)
+      end
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      @result = begin;  text.strip ; end
+      _tmp = true
+      unless _tmp
+        self.pos = _save
+      end
+      break
+    end # end sequence
+
+    set_failed_rule :_TableItem unless _tmp
+    return _tmp
+  end
+
+  # TableLine = TableColumn+:line "|" @Newline { line }
+  def _TableLine
+
+    _save = self.pos
+    while true # sequence
+      _save1 = self.pos
+      _ary = []
+      _tmp = apply(:_TableColumn)
+      if _tmp
+        _ary << @result
+        while true
+          _tmp = apply(:_TableColumn)
+          _ary << @result if _tmp
+          break unless _tmp
+        end
+        _tmp = true
+        @result = _ary
+      else
+        self.pos = _save1
+      end
+      line = @result
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _tmp = match_string("|")
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _tmp = _Newline()
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      @result = begin;  line ; end
+      _tmp = true
+      unless _tmp
+        self.pos = _save
+      end
+      break
+    end # end sequence
+
+    set_failed_rule :_TableLine unless _tmp
+    return _tmp
+  end
+
+  # TableColumn = "|" < ("-"+ ":"? | ":" "-"*) > { text.start_with?(":") ? :left :                 text.end_with?(":") ? :right : nil               }
+  def _TableColumn
+
+    _save = self.pos
+    while true # sequence
+      _tmp = match_string("|")
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _text_start = self.pos
+
+      _save1 = self.pos
+      while true # choice
+
+        _save2 = self.pos
+        while true # sequence
+          _save3 = self.pos
+          _tmp = match_string("-")
+          if _tmp
+            while true
+              _tmp = match_string("-")
+              break unless _tmp
+            end
+            _tmp = true
+          else
+            self.pos = _save3
+          end
+          unless _tmp
+            self.pos = _save2
+            break
+          end
+          _save4 = self.pos
+          _tmp = match_string(":")
+          unless _tmp
+            _tmp = true
+            self.pos = _save4
+          end
+          unless _tmp
+            self.pos = _save2
+          end
+          break
+        end # end sequence
+
+        break if _tmp
+        self.pos = _save1
+
+        _save5 = self.pos
+        while true # sequence
+          _tmp = match_string(":")
+          unless _tmp
+            self.pos = _save5
+            break
+          end
+          while true
+            _tmp = match_string("-")
+            break unless _tmp
+          end
+          _tmp = true
+          unless _tmp
+            self.pos = _save5
+          end
+          break
+        end # end sequence
+
+        break if _tmp
+        self.pos = _save1
+        break
+      end # end choice
+
+      if _tmp
+        text = get_text(_text_start)
+      end
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      @result = begin;  text.start_with?(":") ? :left :
+                text.end_with?(":") ? :right : nil
+              ; end
+      _tmp = true
+      unless _tmp
+        self.pos = _save
+      end
+      break
+    end # end sequence
+
+    set_failed_rule :_TableColumn unless _tmp
+    return _tmp
+  end
+
   # DefinitionList = &{ definition_lists? } DefinitionListItem+:list { RDoc::Markup::List.new :NOTE, *list.flatten }
   def _DefinitionList
 
@@ -16046,7 +16439,7 @@ class RDoc::Markdown
   Rules = {}
   Rules[:_root] = rule_info("root", "Doc")
   Rules[:_Doc] = rule_info("Doc", "BOM? Block*:a { RDoc::Markup::Document.new(*a.compact) }")
-  Rules[:_Block] = rule_info("Block", "@BlankLine* (BlockQuote | Verbatim | CodeFence | Note | Reference | HorizontalRule | Heading | OrderedList | BulletList | DefinitionList | HtmlBlock | StyleBlock | Para | Plain)")
+  Rules[:_Block] = rule_info("Block", "@BlankLine* (BlockQuote | Verbatim | CodeFence | Table | Note | Reference | HorizontalRule | Heading | OrderedList | BulletList | DefinitionList | HtmlBlock | StyleBlock | Para | Plain)")
   Rules[:_Para] = rule_info("Para", "@NonindentSpace Inlines:a @BlankLine+ { paragraph a }")
   Rules[:_Plain] = rule_info("Plain", "Inlines:a { paragraph a }")
   Rules[:_AtxInline] = rule_info("AtxInline", "!@Newline !(@Sp /\#*/ @Sp @Newline) Inline")
@@ -16190,7 +16583,7 @@ class RDoc::Markdown
   Rules[:_StyleClose] = rule_info("StyleClose", "\"<\" Spnl \"/\" (\"style\" | \"STYLE\") Spnl \">\"")
   Rules[:_InStyleTags] = rule_info("InStyleTags", "StyleOpen (!StyleClose .)* StyleClose")
   Rules[:_StyleBlock] = rule_info("StyleBlock", "< InStyleTags > @BlankLine* { if css? then                     RDoc::Markup::Raw.new text                   end }")
-  Rules[:_Inlines] = rule_info("Inlines", "(!@Endline Inline:i { i } | @Endline:c &Inline { c })+:chunks @Endline? { chunks }")
+  Rules[:_Inlines] = rule_info("Inlines", "(!@Endline Inline:i { i } | @Endline:c !(&{ github? } Ticks3 /[^`\\n]*$/) &Inline { c })+:chunks @Endline? { chunks }")
   Rules[:_Inline] = rule_info("Inline", "(Str | @Endline | UlOrStarLine | @Space | Strong | Emph | Strike | Image | Link | NoteReference | InlineNote | Code | RawHtml | Entity | EscapedChar | Symbol)")
   Rules[:_Space] = rule_info("Space", "@Spacechar+ { \" \" }")
   Rules[:_Str] = rule_info("Str", "@StartList:a < @NormalChar+ > { a = text } (StrChunk:c { a << c })* { a }")
@@ -16279,6 +16672,11 @@ class RDoc::Markdown
   Rules[:_Notes] = rule_info("Notes", "(Note | SkipBlock)*")
   Rules[:_RawNoteBlock] = rule_info("RawNoteBlock", "@StartList:a (!@BlankLine OptionallyIndentedLine:l { a << l })+ < @BlankLine* > { a << text } { a }")
   Rules[:_CodeFence] = rule_info("CodeFence", "&{ github? } Ticks3 (@Sp StrChunk:format)? Spnl < ((!\"`\" Nonspacechar)+ | !Ticks3 /`+/ | Spacechar | @Newline)+ > Ticks3 @Sp @Newline* { verbatim = RDoc::Markup::Verbatim.new text               verbatim.format = format.intern if format.instance_of?(String)               verbatim             }")
+  Rules[:_Table] = rule_info("Table", "&{ github? } TableRow:header TableLine:line TableRow+:body { table = RDoc::Markup::Table.new(header, line, body) }")
+  Rules[:_TableRow] = rule_info("TableRow", "TableItem+:row \"|\" @Newline { row }")
+  Rules[:_TableItem] = rule_info("TableItem", "\"|\" < (!\"|\" !@Newline .)+ > { text.strip }")
+  Rules[:_TableLine] = rule_info("TableLine", "TableColumn+:line \"|\" @Newline { line }")
+  Rules[:_TableColumn] = rule_info("TableColumn", "\"|\" < (\"-\"+ \":\"? | \":\" \"-\"*) > { text.start_with?(\":\") ? :left :                 text.end_with?(\":\") ? :right : nil               }")
   Rules[:_DefinitionList] = rule_info("DefinitionList", "&{ definition_lists? } DefinitionListItem+:list { RDoc::Markup::List.new :NOTE, *list.flatten }")
   Rules[:_DefinitionListItem] = rule_info("DefinitionListItem", "DefinitionListLabel+:label DefinitionListDefinition+:defns { list_items = []                        list_items <<                          RDoc::Markup::ListItem.new(label, defns.shift)                         list_items.concat defns.map { |defn|                          RDoc::Markup::ListItem.new nil, defn                        } unless list_items.empty?                         list_items                      }")
   Rules[:_DefinitionListLabel] = rule_info("DefinitionListLabel", "StrChunk:label @Sp @Newline { label }")
diff --git a/lib/rdoc/markup.rb b/lib/rdoc/markup.rb
index fd59fca314..92aed757cf 100644
--- a/lib/rdoc/markup.rb
+++ b/lib/rdoc/markup.rb
@@ -843,6 +843,7 @@ https://github.com/ruby/rdoc/issues
   autoload :List,                  'rdoc/markup/list'
   autoload :ListItem,              'rdoc/markup/list_item'
   autoload :Paragraph,             'rdoc/markup/paragraph'
+  autoload :Table,                 'rdoc/markup/table'
   autoload :Raw,                   'rdoc/markup/raw'
   autoload :Rule,                  'rdoc/markup/rule'
   autoload :Verbatim,              'rdoc/markup/verbatim'
diff --git a/lib/rdoc/markup/attr_span.rb b/lib/rdoc/markup/attr_span.rb
index 63aace60d2..20ef11cd6d 100644
--- a/lib/rdoc/markup/attr_span.rb
+++ b/lib/rdoc/markup/attr_span.rb
@@ -7,16 +7,22 @@ class RDoc::Markup::AttrSpan
   ##
   # Creates a new AttrSpan for +length+ characters
 
-  def initialize(length)
+  def initialize(length, exclusive)
     @attrs = Array.new(length, 0)
+    @exclusive = exclusive
   end
 
   ##
   # Toggles +bits+ from +start+ to +length+
   def set_attrs(start, length, bits)
+    updated = false
     for i in start ... (start+length)
-      @attrs[i] |= bits
+      if (@exclusive & @attrs[i]) == 0 || (@exclusive & bits) != 0
+        @attrs[i] |= bits
+        updated = true
+      end
     end
+    updated
   end
 
   ##
diff --git a/lib/rdoc/markup/attribute_manager.rb b/lib/rdoc/markup/attribute_manager.rb
index f052bc8b01..50764510f3 100644
--- a/lib/rdoc/markup/attribute_manager.rb
+++ b/lib/rdoc/markup/attribute_manager.rb
@@ -59,6 +59,10 @@ class RDoc::Markup::AttributeManager
   attr_reader :regexp_handlings
 
   ##
+  # A bits of exclusive maps
+  attr_reader :exclusive_bitmap
+
+  ##
   # Creates a new attribute manager that understands bold, emphasized and
   # teletype text.
 
@@ -68,17 +72,18 @@ class RDoc::Markup::AttributeManager
     @protectable = %w[<]
     @regexp_handlings = []
     @word_pair_map = {}
+    @exclusive_bitmap = 0
     @attributes = RDoc::Markup::Attributes.new
 
-    add_word_pair "*", "*", :BOLD
-    add_word_pair "_", "_", :EM
-    add_word_pair "+", "+", :TT
+    add_word_pair "*", "*", :BOLD, true
+    add_word_pair "_", "_", :EM, true
+    add_word_pair "+", "+", :TT, true
 
-    add_html "em", :EM
-    add_html "i",  :EM
-    add_html "b",  :BOLD
-    add_html "tt",   :TT
-    add_html "code", :TT
+    add_html "em", :EM, true
+    add_html "i",  :EM, true
+    add_html "b",  :BOLD, true
+    add_html "tt",   :TT, true
+    add_html "code", :TT, true
   end
 
   ##
@@ -122,29 +127,67 @@ class RDoc::Markup::AttributeManager
     res
   end
 
+  def exclusive?(attr)
+    (attr & @exclusive_bitmap) != 0
+  end
+
+  NON_PRINTING_START = "\1" # :nodoc:
+  NON_PRINTING_END = "\2" # :nodoc:
+
   ##
   # Map attributes like <b>text</b>to the sequence
   # \001\002<char>\001\003<char>, where <char> is a per-attribute specific
   # character
 
-  def convert_attrs(str, attrs)
+  def convert_attrs(str, attrs, exclusive = false)
+    convert_attrs_matching_word_pairs(str, attrs, exclusive)
+    convert_attrs_word_pair_map(str, attrs, exclusive)
+  end
+
+  def convert_attrs_matching_word_pairs(str, attrs, exclusive)
     # first do matching ones
-    tags = @matching_word_pairs.keys.join("")
+    tags = @matching_word_pairs.select { |start, bitmap|
+      if exclusive && exclusive?(bitmap)
+        true
+      elsif !exclusive && !exclusive?(bitmap)
+        true
+      else
+        false
+      end
+    }.keys
+    return if tags.empty?
+    all_tags = @matching_word_pairs.keys
 
-    re = /(^|\W)([#{tags}])([#\\]?[\w:.\/-]+?\S?)\2(\W|$)/
+    re = /(^|\W|[#{all_tags.join("")}])([#{tags.join("")}])(\2*[#\\]?[\w:.\/\[\]-]+?\S?)\2(?!\2)([#{all_tags.join("")}]|\W|$)/
 
-    1 while str.gsub!(re) do
+    1 while str.gsub!(re) { |orig|
       attr = @matching_word_pairs[$2]
-      attrs.set_attrs($`.length + $1.length + $2.length, $3.length, attr)
-      $1 + NULL * $2.length + $3 + NULL * $2.length + $4
-    end
+      attr_updated = attrs.set_attrs($`.length + $1.length + $2.length, $3.length, attr)
+      if attr_updated
+        $1 + NULL * $2.length + $3 + NULL * $2.length + $4
+      else
+        $1 + NON_PRINTING_START + $2 + NON_PRINTING_END + $3 + NON_PRINTING_START + $2 + NON_PRINTING_END + $4
+      end
+    }
+    str.delete!(NON_PRINTING_START + NON_PRINTING_END)
+  end
 
+  def convert_attrs_word_pair_map(str, attrs, exclusive)
     # then non-matching
     unless @word_pair_map.empty? then
       @word_pair_map.each do |regexp, attr|
-        str.gsub!(regexp) {
-          attrs.set_attrs($`.length + $1.length, $2.length, attr)
-          NULL * $1.length + $2 + NULL * $3.length
+        if !exclusive
+          next if exclusive?(attr)
+        else
+          next if !exclusive?(attr)
+        end
+        1 while str.gsub!(regexp) { |orig|
+          updated = attrs.set_attrs($`.length + $1.length, $2.length, attr)
+          if updated
+            NULL * $1.length + $2 + NULL * $3.length
+          else
+            orig
+          end
         }
       end
     end
@@ -153,10 +196,18 @@ class RDoc::Markup::AttributeManager
   ##
   # Converts HTML tags to RDoc attributes
 
-  def convert_html(str, attrs)
-    tags = @html_tags.keys.join '|'
+  def convert_html(str, attrs, exclusive = false)
+    tags = @html_tags.select { |start, bitmap|
+      if exclusive && exclusive?(bitmap)
+        true
+      elsif !exclusive && !exclusive?(bitmap)
+        true
+      else
+        false
+      end
+    }.keys.join '|'
 
-    1 while str.gsub!(/<(#{tags})>(.*?)<\/\1>/i) {
+    1 while str.gsub!(/<(#{tags})>(.*?)<\/\1>/i) { |orig|
       attr = @html_tags[$1.downcase]
       html_length = $1.length + 2
       seq = NULL * html_length
@@ -168,8 +219,13 @@ class RDoc::Markup::AttributeManager
   ##
   # Converts regexp handling sequences to RDoc attributes
 
-  def convert_regexp_handlings str, attrs
+  def convert_regexp_handlings str, attrs, exclusive = false
     @regexp_handlings.each do |regexp, attribute|
+      if exclusive
+        next if !exclusive?(attribute)
+      else
+        next if exclusive?(attribute)
+      end
       str.scan(regexp) do
         capture = $~.size == 1 ? 0 : 1
 
@@ -205,7 +261,7 @@ class RDoc::Markup::AttributeManager
   #
   #   am.add_word_pair '*', '*', :BOLD
 
-  def add_word_pair(start, stop, name)
+  def add_word_pair(start, stop, name, exclusive = false)
     raise ArgumentError, "Word flags may not start with '<'" if
       start[0,1] == '<'
 
@@ -220,6 +276,8 @@ class RDoc::Markup::AttributeManager
 
     @protectable << start[0,1]
     @protectable.uniq!
+
+    @exclusive_bitmap |= bitmap if exclusive
   end
 
   ##
@@ -228,8 +286,10 @@ class RDoc::Markup::AttributeManager
   #
   #   am.add_html 'em', :EM
 
-  def add_html(tag, name)
-    @html_tags[tag.downcase] = @attributes.bitmap_for name
+  def add_html(tag, name, exclusive = false)
+    bitmap = @attributes.bitmap_for name
+    @html_tags[tag.downcase] = bitmap
+    @exclusive_bitmap |= bitmap if exclusive
   end
 
   ##
@@ -238,8 +298,10 @@ class RDoc::Markup::AttributeManager
   #
   #   @am.add_regexp_handling(/((https?:)\S+\w)/, :HYPERLINK)
 
-  def add_regexp_handling pattern, name
-    @regexp_handlings << [pattern, @attributes.bitmap_for(name)]
+  def add_regexp_handling pattern, name, exclusive = false
+    bitmap = @attributes.bitmap_for(name)
+    @regexp_handlings << [pattern, bitmap]
+    @exclusive_bitmap |= bitmap if exclusive
   end
 
   ##
@@ -250,8 +312,11 @@ class RDoc::Markup::AttributeManager
 
     mask_protected_sequences
 
-    @attrs = RDoc::Markup::AttrSpan.new @str.length
+    @attrs = RDoc::Markup::AttrSpan.new @str.length, @exclusive_bitmap
 
+    convert_attrs            @str, @attrs, true
+    convert_html             @str, @attrs, true
+    convert_regexp_handlings @str, @attrs, true
     convert_attrs            @str, @attrs
     convert_html             @str, @attrs
     convert_regexp_handlings @str, @attrs
diff --git a/lib/rdoc/markup/table.rb b/lib/rdoc/markup/table.rb
new file mode 100644
index 0000000000..7bcb10aff3
--- /dev/null
+++ b/lib/rdoc/markup/table.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+##
+# A section of table
+
+class RDoc::Markup::Table
+  attr_accessor :header, :align, :body
+
+  def initialize header, align, body
+    @header, @align, @body = header, align, body
+  end
+
+  def == other
+    self.class == other.class and
+      @header == other.header and
+      @align == other.align and
+      @body == other.body
+  end
+
+  def accept visitor
+    visitor.accept_table @header, @body, @align
+  end
+
+  def pretty_print q # :nodoc:
+    q.group 2, '[Table: ', ']' do
+      q.group 2, '[Head: ', ']' do
+        q.seplist @header.zip(@align) do |text, align|
+          q.pp text
+          if align
+            q.text ":"
+            q.breakable
+            q.text align.to_s
+          end
+        end
+      end
+      q.breakable
+      q.group 2, '[Body: ', ']' do
+        q.seplist @body do |body|
+          q.group 2, '[', ']' do
+            q.seplist body do |text|
+              q.pp text
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/rdoc/markup/to_html.rb b/lib/rdoc/markup/to_html.rb
index 3b1b0e9d40..8ae4dd4720 100644
--- a/lib/rdoc/markup/to_html.rb
+++ b/lib/rdoc/markup/to_html.rb
@@ -314,6 +314,29 @@ class RDoc::Markup::ToHtml < RDoc::Markup::Formatter
     @res << raw.parts.join("\n")
   end
 
+  ##
+  # Adds +table+ to the output
+
+  def accept_table header, body, aligns
+    @res << "\n<table role=\"table\">\n<thead>\n<tr>\n"
+    header.zip(aligns) do |text, align|
+      @res << '<th'
+      @res << ' align="' << align << '"' if align
+      @res << '>' << CGI.escapeHTML(text) << "</th>\n"
+    end
+    @res << "</tr>\n</thead>\n<tbody>\n"
+    body.each do |row|
+      @res << "<tr>\n"
+      row.zip(aligns) do |text, align|
+        @res << '<td'
+        @res << ' align="' << align << '"' if align
+        @res << '>' << CGI.escapeHTML(text) << "</td>\n"
+      end
+      @res << "</tr>\n"
+    end
+    @res << "</tbody>\n</table>\n"
+  end
+
   # :section: Utilities
 
   ##
@@ -334,6 +357,10 @@ class RDoc::Markup::ToHtml < RDoc::Markup::Formatter
        url =~ /\.(gif|png|jpg|jpeg|bmp)$/ then
       "<img src=\"#{url}\" />"
     else
+      if scheme != 'link' and /\.(?:rb|rdoc|md)\z/i =~ url
+        url = url.sub(%r%\A([./]*)(.*)\z%) { "#$1#{$2.tr('.', '_')}.html" }
+      end
+
       text = text.sub %r%^#{scheme}:/*%i, ''
       text = text.sub %r%^[*\^](\d+)$%,   '\1'
 
diff --git a/lib/rdoc/markup/to_joined_paragraph.rb b/lib/rdoc/markup/to_joined_paragraph.rb
index 795f3f62ee..46e07c94ad 100644
--- a/lib/rdoc/markup/to_joined_paragraph.rb
+++ b/lib/rdoc/markup/to_joined_paragraph.rb
@@ -41,6 +41,7 @@ class RDoc::Markup::ToJoinedParagraph < RDoc::Markup::Formatter
   alias accept_raw             ignore
   alias accept_rule            ignore
   alias accept_verbatim        ignore
+  alias accept_table           ignore
 
 end
 
diff --git a/lib/rdoc/markup/to_rdoc.rb b/lib/rdoc/markup/to_rdoc.rb
index 81b16c4973..3cdf4fd08b 100644
--- a/lib/rdoc/markup/to_rdoc.rb
+++ b/lib/rdoc/markup/to_rdoc.rb
@@ -238,6 +238,34 @@ class RDoc::Markup::ToRdoc < RDoc::Markup::Formatter
   end
 
   ##
+  # Adds +table+ to the output
+
+  def accept_table header, body, aligns
+    widths = header.zip(body) do |h, b|
+      [h.size, b.size].max
+    end
+    aligns = aligns.map do |a|
+      case a
+      when nil
+        :center
+      when :left
+        :ljust
+      when :right
+        :rjust
+      end
+    end
+    @res << header.zip(widths, aligns) do |h, w, a|
+      h.__send__(a, w)
+    end.join("|").rstrip << "\n"
+    @res << widths.map {|w| "-" * w }.join("|") << "\n"
+    body.each do |row|
+      @res << row.zip(widths, aligns) do |t, w, a|
+        t.__send__(a, w)
+      end.join("|").rstrip << "\n"
+    end
+  end
+
+  ##
   # Applies attribute-specific markup to +text+ using RDoc::AttributeManager
 
   def attributes text
diff --git a/lib/rdoc/markup/to_table_of_contents.rb b/lib/rdoc/markup/to_table_of_contents.rb
index f68b90bcf6..eb8e8faa16 100644
--- a/lib/rdoc/markup/to_table_of_contents.rb
+++ b/lib/rdoc/markup/to_table_of_contents.rb
@@ -82,6 +82,7 @@ class RDoc::Markup::ToTableOfContents < RDoc::Markup::Formatter
   alias accept_list_item_end   ignore
   alias accept_list_end_bullet ignore
   alias accept_list_start      ignore
+  alias accept_table           ignore
   # :startdoc:
 
 end
diff --git a/lib/rdoc/options.rb b/lib/rdoc/options.rb
index 13c1abae0a..13b7ba5c6c 100644
--- a/lib/rdoc/options.rb
+++ b/lib/rdoc/options.rb
@@ -338,8 +338,9 @@ class RDoc::Options
 
   attr_reader :visibility
 
-  def initialize # :nodoc:
+  def initialize loaded_options = nil # :nodoc:
     init_ivars
+    override loaded_options if loaded_options
   end
 
   def init_ivars # :nodoc:
@@ -417,6 +418,37 @@ class RDoc::Options
     init_with map
   end
 
+  def override map # :nodoc:
+    if map.has_key?('encoding')
+      encoding = map['encoding']
+      @encoding = encoding ? Encoding.find(encoding) : encoding
+    end
+
+    @charset        = map['charset']        if map.has_key?('charset')
+    @exclude        = map['exclude']        if map.has_key?('exclude')
+    @generator_name = map['generator_name'] if map.has_key?('generator_name')
+    @hyperlink_all  = map['hyperlink_all']  if map.has_key?('hyperlink_all')
+    @line_numbers   = map['line_numbers']   if map.has_key?('line_numbers')
+    @locale_name    = map['locale_name']    if map.has_key?('locale_name')
+    @locale_dir     = map['locale_dir']     if map.has_key?('locale_dir')
+    @main_page      = map['main_page']      if map.has_key?('main_page')
+    @markup         = map['markup']         if map.has_key?('markup')
+    @op_dir         = map['op_dir']         if map.has_key?('op_dir')
+    @show_hash      = map['show_hash']      if map.has_key?('show_hash')
+    @tab_width      = map['tab_width']      if map.has_key?('tab_width')
+    @template_dir   = map['template_dir']   if map.has_key?('template_dir')
+    @title          = map['title']          if map.has_key?('title')
+    @visibility     = map['visibility']     if map.has_key?('visibility')
+    @webcvs         = map['webcvs']         if map.has_key?('webcvs')
+
+    if map.has_key?('rdoc_include')
+      @rdoc_include = sanitize_path map['rdoc_include']
+    end
+    if map.has_key?('static_path')
+      @static_path  = sanitize_path map['static_path']
+    end
+  end
+
   def == other # :nodoc:
     self.class === other and
       @encoding       == other.encoding       and
diff --git a/lib/rdoc/parser/changelog.rb b/lib/rdoc/parser/changelog.rb
index 167892f543..9245d49376 100644
--- a/lib/rdoc/parser/changelog.rb
+++ b/lib/rdoc/parser/changelog.rb
@@ -1,5 +1,4 @@
 # frozen_string_literal: true
-require 'time'
 
 ##
 # A ChangeLog file parser.
@@ -106,15 +105,33 @@ class RDoc::Parser::ChangeLog < RDoc::Parser
     entries.group_by do |title, _|
       begin
         time = @time_cache[title]
-        (time || Time.parse(title)).strftime '%Y-%m-%d'
+        (time || parse_date(title)).strftime '%Y-%m-%d'
       rescue NoMethodError, ArgumentError
         time, = title.split '  ', 2
-        Time.parse(time).strftime '%Y-%m-%d'
+        parse_date(time).strftime '%Y-%m-%d'
       end
     end
   end
 
   ##
+  # Parse date in ISO-8601, RFC-2822, or default of Git
+
+  def parse_date(date)
+    case date
+    when /\A\s*(\d+)-(\d+)-(\d+)(?:[ T](\d+):(\d+):(\d+) *([-+]\d\d):?(\d\d))?\b/
+      Time.new($1, $2, $3, $4, $5, $6, ("#{$7}:#{$8}" if $7))
+    when /\A\s*\w{3}, +(\d+) (\w{3}) (\d+) (\d+):(\d+):(\d+) *(?:([-+]\d\d):?(\d\d))\b/
+      Time.new($3, $2, $1, $4, $5, $6, ("#{$7}:#{$8}" if $7))
+    when /\A\s*\w{3} (\w{3}) +(\d+) (\d+) (\d+):(\d+):(\d+) *(?:([-+]\d\d):?(\d\d))\b/
+      Time.new($3, $1, $2, $4, $5, $6, ("#{$7}:#{$8}" if $7))
+    when /\A\s*\w{3} (\w{3}) +(\d+) (\d+):(\d+):(\d+) (\d+)\b/
+      Time.new($6, $1, $2, $3, $4, $5)
+    else
+      raise ArgumentError, "bad date: #{date}"
+    end
+  end
+
+  ##
   # Parses the entries in the ChangeLog.
   #
   # Returns an Array of each ChangeLog entry in order of parsing.
@@ -131,6 +148,13 @@ class RDoc::Parser::ChangeLog < RDoc::Parser
 
   def parse_entries
     @time_cache ||= {}
+
+    if /\A((?:.*\n){,3})commit\s/ =~ @content
+      class << self; prepend Git; end
+      parse_info($1)
+      return parse_entries
+    end
+
     entries = []
     entry_name = nil
     entry_body = []
@@ -145,19 +169,10 @@ class RDoc::Parser::ChangeLog < RDoc::Parser
         entry_name = $&
 
         begin
-          time = Time.parse entry_name
+          time = parse_date entry_name
           @time_cache[entry_name] = time
-          # HACK Ruby 1.8 does not raise ArgumentError for Time.parse "Other"
-          entry_name = nil unless entry_name =~ /#{time.year}/
-        rescue NoMethodError
-          # HACK Ruby 2.1.2 and earlier raises NoMethodError if time part is absent
-          entry_name.split '  ', 2
         rescue ArgumentError
-          if /out of range/ =~ $!.message
-            Time.parse(entry_name.split('  ', 2)[0]) rescue entry_name = nil
-          else
-            entry_name = nil
-          end
+          entry_name = nil
         end
 
         entry_body = []
@@ -190,6 +205,7 @@ class RDoc::Parser::ChangeLog < RDoc::Parser
 
   def scan
     @time_cache = {}
+
     entries = parse_entries
     grouped_entries = group_entries entries
 
@@ -200,5 +216,120 @@ class RDoc::Parser::ChangeLog < RDoc::Parser
     @top_level
   end
 
+  module Git
+    def parse_info(info)
+      /^\s*base-url\s*=\s*(.*\S)/ =~ info
+      @base_url = $1
+    end
+
+    def parse_entries
+      entries = []
+
+      @content.scan(/^commit\s+(\h{20})\h*\n((?:.+\n)*)\n((?: {4}.*\n+)*)/) do
+        entry_name, header, entry_body = $1, $2, $3.gsub(/^ {4}/, '')
+        # header = header.scan(/^ *(\S+?): +(.*)/).to_h
+        # date = header["CommitDate"] || header["Date"]
+        date = header[/^ *(?:Author)?Date: +(.*)/, 1]
+        author = header[/^ *Author: +(.*)/, 1]
+        begin
+          time = parse_date(header[/^ *CommitDate: +(.*)/, 1] || date)
+          @time_cache[entry_name] = time
+          author.sub!(/\s*<(.*)>/, '')
+          email = $1
+          entries << [entry_name, [author, email, date, entry_body]]
+        rescue ArgumentError
+        end
+      end
+
+      entries
+    end
+
+    def create_entries entries
+      # git log entries have no strictly itemized style like the old
+      # style, just assume Markdown.
+      entries.map do |commit, entry|
+        LogEntry.new(@base_url, commit, *entry)
+      end
+    end
+
+    LogEntry = Struct.new(:base, :commit, :author, :email, :date, :contents) do
+      HEADING_LEVEL = 3
+
+      def initialize(base, commit, author, email, date, contents)
+        case contents
+        when String
+          contents = RDoc::Markdown.parse(contents).parts.each do |body|
+            case body
+            when RDoc::Markup::Heading
+              body.level += HEADING_LEVEL + 1
+            end
+          end
+          case first = contents[0]
+          when RDoc::Markup::Paragraph
+            contents[0] = RDoc::Markup::Heading.new(HEADING_LEVEL + 1, first.text)
+          end
+        end
+        super
+      end
+
+      def level
+        HEADING_LEVEL
+      end
+
+      def aref
+        "label-#{commit}"
+      end
+
+      def label context = nil
+        aref
+      end
+
+      def text
+        case base
+        when nil
+          "#{date}"
+        when /%s/
+          "{#{date}}[#{base % commit}]"
+        else
+          "{#{date}}[#{base}#{commit}]"
+        end + " {#{author}}[mailto:#{email}]"
+      end
+
+      def accept visitor
+        visitor.accept_heading self
+        begin
+          if visitor.respond_to?(:code_object=)
+            code_object = visitor.code_object
+            visitor.code_object = self
+          end
+          contents.each do |body|
+            body.accept visitor
+          end
+        ensure
+          if visitor.respond_to?(:code_object)
+            visitor.code_object = code_object
+          end
+        end
+      end
+
+      def pretty_print q # :nodoc:
+        q.group(2, '[log_entry: ', ']') do
+          q.text commit
+          q.text ','
+          q.breakable
+          q.group(2, '[date: ', ']') { q.text date }
+          q.text ','
+          q.breakable
+          q.group(2, '[author: ', ']') { q.text author }
+          q.text ','
+          q.breakable
+          q.group(2, '[email: ', ']') { q.text email }
+          q.text ','
+          q.breakable
+          q.pp contents
+        end
+      end
+    end
+  end
 end
 
diff --git a/lib/rdoc/rdoc.rb b/lib/rdoc/rdoc.rb
index 93e764c462..bb58513d2c 100644
--- a/lib/rdoc/rdoc.rb
+++ b/lib/rdoc/rdoc.rb
@@ -166,8 +166,15 @@ class RDoc::RDoc
     rescue Psych::SyntaxError
     end
 
+    return RDoc::Options.new if options == false # Allow empty file.
+
     raise RDoc::Error, "#{options_file} is not a valid rdoc options file" unless
-      RDoc::Options === options
+      RDoc::Options === options or Hash === options
+
+    if Hash === options
+      # Override the default values with the contents of YAML file.
+      options = RDoc::Options.new options
+    end
 
     options
   end
@@ -436,7 +443,7 @@ The internal error was:
     files.reject do |file, *|
       file =~ /\.(?:class|eps|erb|scpt\.txt|svg|ttf|yml)$/i or
         (file =~ /tags$/i and
-         open(file, 'rb') { |io|
+         File.open(file, 'rb') { |io|
            io.read(100) =~ /\A(\f\n[^,]+,\d+$|!_TAG_)/
          })
     end
diff --git a/lib/rdoc/version.rb b/lib/rdoc/version.rb
index bfb442c5c9..f6e18f7d4d 100644
--- a/lib/rdoc/version.rb
+++ b/lib/rdoc/version.rb
@@ -3,6 +3,6 @@ module RDoc
   ##
   # RDoc version you are using
 
-  VERSION = '6.3.0'
+  VERSION = '6.3.1'
 
 end