merge revision(s) 51871,51872,51874,51875,51876,51877,51878,57517: [Backport #13190]

	* doc/syntax/literals.rdoc (Strings): mention about ?a literal.

	literals.rdoc: fix typos

	* doc/syntax/literals.rdoc (Strings): fix typos.
	* doc/syntax/literals.rdoc (Strings): [DOC] Document the full list
	  of supported escape sequences in string literals.

	* doc/syntax/literals.rdoc (Strings): [DOC] Revise the character
	  literal part.

	literals.rdoc: add DEL [ci skip]

	* doc/syntax/literals.rdoc (Strings): [DOC] add DEL.
	[DOC] `\0` is interpreted as NUL only if not followed by an octal digit.
	[DOC] Remove `\0` since it's aprt of octal notation

	A typo is fixed while at it.
	doc: Fix error for escape sequences in string literals

	Backslash goes first in escape sequences, so it must be
	"any other character following a backslash is interpreted as ...",
	while the doc says "...followed by...".

	Author: Marcus Stollsteimer <sto.mar@web.de>
	[ruby-core:79418] [Bug #13190]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_2@58114 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 59 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index d6a1de9f75..9ed2482715 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+Sun Mar 26 02:44:16 2017  Akinori MUSHA  <knu@iDaemons.org>
+
+	* doc/syntax/literals.rdoc (Strings): [DOC] Revise the character
+	  literal part.
+
+Sun Mar 26 02:44:16 2017  Akinori MUSHA  <knu@iDaemons.org>
+
+	* doc/syntax/literals.rdoc (Strings): [DOC] Document the full list
+	  of supported escape sequences in string literals.
+
+Sun Mar 26 02:44:16 2017  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* doc/syntax/literals.rdoc (Strings): mention about ?a literal.
+
 Sun Mar 26 02:35:17 2017  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.c (process_options): convert -e script to the encoding
diff --git a/doc/syntax/literals.rdoc b/doc/syntax/literals.rdoc
index 194945abbd..aadd574a97 100644
--- a/doc/syntax/literals.rdoc
+++ b/doc/syntax/literals.rdoc
@@ -83,8 +83,33 @@ Any internal <tt>"</tt> must be escaped:
 
   "This string has a quote: \".  As you can see, it is escaped"
 
-Double-quote strings allow escaped characters such as <tt>\n</tt> for newline,
-<tt>\t</tt> for tab, etc.
+Double-quote strings allow escaped characters such as <tt>\n</tt> for
+newline, <tt>\t</tt> for tab, etc.  The full list of supported escape
+sequences are as follows:
+
+  \a             bell, ASCII 07h (BEL)
+  \b             backspace, ASCII 08h (BS)
+  \t             horizontal tab, ASCII 09h (TAB)
+  \n             newline (line feed), ASCII 0Ah (LF)
+  \v             vertical tab, ASCII 0Bh (VT)
+  \f             form feed, ASCII 0Ch (FF)
+  \r             carriage return, ASCII 0Dh (CR)
+  \e             escape, ASCII 1Bh (ESC)
+  \s             space, ASCII 20h (SPC)
+  \\             backslash, \
+  \nnn           octal bit pattern, where nnn is 1-3 octal digits ([0-7])
+  \xnn           hexadecimal bit pattern, where nn is 1-2 hexadecimal digits ([0-9a-fA-F])
+  \unnnn         Unicode character, where nnnn is exactly 4 hexadecimal digits ([0-9a-fA-F])
+  \u{nnnn ...}   Unicode character(s), where each nnnn is 1-6 hexadecimal digits ([0-9a-fA-F])
+  \cx or \C-x    control character, where x is an ASCII printable character
+  \M-x           meta character, where x is an ASCII printable character
+  \M-\C-x        meta control character, where x is an ASCII printable character
+  \M-\cx         same as above
+  \c\M-x         same as above
+  \c? or \C-?    delete, ASCII 7Fh (DEL)
+
+Any other character following a backslash is interpreted as the
+character itself.
 
 Double-quote strings allow interpolation of other values using
 <tt>#{...}</tt>:
@@ -124,6 +149,23 @@ be concatenated as long as a percent-string is not last.
   %q{a} 'b' "c" #=> "abc"
   "a" 'b' %q{c} #=> NameError: uninitialized constant q
 
+One more way of writing strings is using <tt>?</tt>:
+
+  ?a #=> "a"
+
+Basically only one character can be placed after <tt>?</tt>:
+
+  ?abc #=> SyntaxError
+
+Exceptionally, <tt>\C-</tt>, <tt>\M-</tt> and their combination are allowed
+before a character.  They mean "control", "meta" and "control-meta"
+respectively:
+
+  ?\C-a    #=> "\x01"
+  ?\M-a    #=> "\xE1"
+  ?\M-\C-a #=> "\x81"
+  ?\C-\M-a #=> "\x81", same as above
+
 === Here Documents
 
 If you are writing a large block of text you may use a "here document" or
diff --git a/version.h b/version.h
index 25e717be87..e14d8b6564 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.2.7"
 #define RUBY_RELEASE_DATE "2017-03-26"
-#define RUBY_PATCHLEVEL 446
+#define RUBY_PATCHLEVEL 447
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 3