* localtime.cc (time2): Add workaround for spring gap problem. Add

	explaining comment.

2 files changed, 27 insertions, 1 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 01ffd362d..1723b188c 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,10 @@
 2009-06-12  Corinna Vinschen  <corinna@vinschen.de>
 
+	* localtime.cc (time2): Add workaround for spring gap problem.  Add
+	explaining comment.
+
+2009-06-12  Corinna Vinschen  <corinna@vinschen.de>
+
 	* Makefile.in (SUBLIBS): Add librt.a.
 	(librt.a): New rule to build librt.a.
 
diff --git a/winsup/cygwin/localtime.cc b/winsup/cygwin/localtime.cc
index 6c05851bd..aa0f735ee 100644
--- a/winsup/cygwin/localtime.cc
+++ b/winsup/cygwin/localtime.cc
@@ -1989,7 +1989,28 @@ time2(struct tm *tmp, void (*funcp) P((const time_t*, long, struct tm*)),
 	** If that fails, try with normalization of seconds.
 	*/
 	t = time2sub(tmp, funcp, offset, okayp, false);
-	return *okayp ? t : time2sub(tmp, funcp, offset, okayp, true);
+	if (*okayp)
+	  return t;
+	t = time2sub(tmp, funcp, offset, okayp, true);
+	if (*okayp)
+	  return t;
+	/* Workaround for the spring gap problem which results in the
+	   autoconf mktime usability test failing.
+	   What we do here is this:  The gap has 3600 seconds.  If we
+	   subtract 3600 from the tm_sec value and get a valid result,
+	   then we can simply add 3600 to the return value and are done.
+	   If the result is still not valid, the problem is not the
+	   spring gap and we can give up. */
+	struct tm tmp2 = *tmp;
+	tmp2.tm_sec -= 3600;
+	t = time2sub(&tmp2, funcp, offset, okayp, true);
+	if (*okayp)
+	  {
+	    if (t + 3600 < t)	/* Sanity check */
+	      return WRONG;
+	    return t + 3600;
+	  }
+	return t;
 }
 
 static time_t