merges r31441,r31442 and r31443 from trunk into ruby_1_9_2.

--
YAML.load time correctly parse usecs smaller than 1 fixes #4571

Signed-off-by: URABE, Shyouhei <shyouhei@ruby-lang.org>
--
ChangeLog for it
--
* ext/syck/rubyext.c (mktime_do): avoid buffer overrun, by
  silently ignoring lesser significant digits.  Required buffer
  length can be computable so you might at first think of
  allocating enough memory space on the fly using alloca().  That
  is a wrong idea because when using alloca there is always risk
  of integer overflow.  A function that accepts outer-process
  resources like this should not blindly trust its inputs.  In
  this particular case we just want to generate miliseconds
  resolution by strtod() so the string in question needs no more
  length than what we originally have.  Ignoring lesser
  significant digits should suffice I believe.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_2@31831 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 13 insertions, 12 deletions

diff --git a/ext/syck/rubyext.c b/ext/syck/rubyext.c
index af52976ff1..1be472e040 100644
--- a/ext/syck/rubyext.c
+++ b/ext/syck/rubyext.c
@@ -225,7 +225,7 @@ mktime_do(struct mktime_arg *arg)
     VALUE hour = INT2FIX(0);
     VALUE min = INT2FIX(0);
     VALUE sec = INT2FIX(0);
-    long usec;
+    double usec;
 
     /* Year*/
     if ( ptr[0] != '\0' && len > 0 ) {
@@ -271,19 +271,20 @@ mktime_do(struct mktime_arg *arg)
     ptr += 2;
     if ( len > ptr - str && *ptr == '.' )
     {
-        char padded[] = "000000";
-        char *end = ptr + 1;
-        char *p = end;
+        char padded[] = "000000.000000";
+        const int padding = 6;
+        const int offset = padding + 1;
+        const char *end = ptr + 1;
+        const char *begin = end;
+        int length;
         while ( isdigit( *end ) ) end++;
-        if (end - p < sizeof(padded)) {
-            MEMCPY(padded, ptr + 1, char, end - (ptr + 1));
-            p = padded;
-        }
-        usec = strtol(p, NULL, 10);
+        length = (int)(end - begin) <= padding ? (int)(end - begin) : padding;
+        MEMCPY(padded, begin, char, length);
+        usec = strtod(padded, NULL);
     }
     else
     {
-        usec = 0;
+        usec = 0.0;
     }
 
     /* Time Zone*/
@@ -311,12 +312,12 @@ mktime_do(struct mktime_arg *arg)
         time = rb_funcall(rb_cTime, s_utc, 6, year, mon, day, hour, min, sec);
         tmp = rb_funcall(time, s_to_i, 0);
         tmp = rb_funcall(tmp, '-', 1, LONG2FIX(tz_offset));
-        return rb_funcall(rb_cTime, s_at, 2, tmp, LONG2NUM(usec));
+        return rb_funcall(rb_cTime, s_at, 2, tmp, rb_float_new(usec));
     }
     else
     {
         /* Make UTC time*/
-        return rb_funcall(rb_cTime, s_utc, 7, year, mon, day, hour, min, sec, LONG2NUM(usec));
+        return rb_funcall(rb_cTime, s_utc, 7, year, mon, day, hour, min, sec, rb_float_new(usec));
     }
 }