merge revision(s) 5d4fff845602872eef072e7611558b5f8762efe0: [Backport #19293]

	Tighten Time.new(string) parsing

	Disallow:

	* Only year-month
	* Only year-month-day
	* Preceding whitespace
	* Trailing whitespace

	Fixes [Bug #19293]
	---
	 test/ruby/test_time.rb | 13 +++++++++++++
	 time.c                 | 13 ++++++++++++-
	 2 files changed, 25 insertions(+), 1 deletion(-)

3 files changed, 26 insertions, 2 deletions

diff --git a/test/ruby/test_time.rb b/test/ruby/test_time.rb
index f47a49d3e0..0faad878fc 100644
--- a/test/ruby/test_time.rb
+++ b/test/ruby/test_time.rb
@@ -75,6 +75,7 @@ class TestTime < Test::Unit::TestCase
       Time.new("2020-12-25 00 +09:00")
     }
 
+    assert_equal(Time.new(2021), Time.new("2021"))
     assert_equal(Time.new(2021, 12, 25, in: "+09:00"), Time.new("2021-12-25+09:00"))
 
     assert_equal(0.123456r, Time.new("2021-12-25 00:00:00.123456 +09:00").subsec)
@@ -138,6 +139,18 @@ class TestTime < Test::Unit::TestCase
     assert_raise_with_message(ArgumentError, /mon out of range/) {
       Time.new("2020-17-25 00:56:17 +0900")
     }
+    assert_raise_with_message(ArgumentError, /no time information/) {
+      Time.new("2020-12")
+    }
+    assert_raise_with_message(ArgumentError, /no time information/) {
+      Time.new("2020-12-02")
+    }
+    assert_raise_with_message(ArgumentError, /can't parse/) {
+      Time.new(" 2020-12-02 00:00:00")
+    }
+    assert_raise_with_message(ArgumentError, /can't parse/) {
+      Time.new("2020-12-02 00:00:00 ")
+    }
   end
 
   def test_time_add()
diff --git a/time.c b/time.c
index f1d327f501..50bdb2bf6b 100644
--- a/time.c
+++ b/time.c
@@ -2525,7 +2525,9 @@ time_init_parse(rb_execution_context_t *ec, VALUE klass, VALUE str, VALUE zone,
     size_t ndigits;
     size_t prec = NIL_P(precision) ? SIZE_MAX : NUM2SIZET(precision);
 
-    while ((ptr < end) && ISSPACE(*ptr)) ptr++;
+    if ((ptr < end) && (ISSPACE(*ptr) || ISSPACE(*(end-1)))) {
+        rb_raise(rb_eArgError, "can't parse: %+"PRIsVALUE, str);
+    }
     year = parse_int(ptr, end, &ptr, &ndigits, true);
     if (NIL_P(year)) {
         rb_raise(rb_eArgError, "can't parse: %+"PRIsVALUE, str);
@@ -2533,6 +2535,9 @@ time_init_parse(rb_execution_context_t *ec, VALUE klass, VALUE str, VALUE zone,
     else if (ndigits < 4) {
         rb_raise(rb_eArgError, "year must be 4 or more digits: %.*s", (int)ndigits, ptr - ndigits);
     }
+    else if (ptr == end) {
+        goto only_year;
+    }
     do {
 #define peekable_p(n) ((ptrdiff_t)(n) < (end - ptr))
 #define peek_n(c, n) (peekable_p(n) && ((unsigned char)ptr[n] == (c)))
@@ -2593,6 +2598,9 @@ time_init_parse(rb_execution_context_t *ec, VALUE klass, VALUE str, VALUE zone,
     if (zend > zstr) {
         zone = rb_str_subseq(str, zstr - begin, zend - zstr);
     }
+    else if (hour == -1) {
+        rb_raise(rb_eArgError, "no time information");
+    }
     if (!NIL_P(subsec)) {
         /* subseconds is the last using ndigits */
         static const size_t TIME_SCALE_NUMDIGITS =
@@ -2609,6 +2617,9 @@ time_init_parse(rb_execution_context_t *ec, VALUE klass, VALUE str, VALUE zone,
         }
     }
 
+only_year:
+    ;
+
     struct vtm vtm = {
         .wday = VTM_WDAY_INITVAL,
         .yday = 0,
diff --git a/version.h b/version.h
index 5532e4cf36..35c6adfc97 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 2
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 104
+#define RUBY_PATCHLEVEL 105
 
 #include "ruby/version.h"
 #include "ruby/internal/abi.h"