Set errno for atan2 underflow (bug 16349).

This patch fixes bug 16349, missing errno setting for atan2 underflow,
by adding appropriate checks to the existing wrappers.  (As in other
cases, the __kernel_standard support for calling matherr is considered
to be for existing code expecting existing rules for what's considered
an error, even if those don't correspond to a general logical scheme
for what counts as what kind of error, so __set_errno calls are added
directly without any changes to __kernel_standard.)

Tested x86_64 and x86.

	[BZ #16349]
	* math/w_atan2.c: Include <errno.h>.
	(__atan2): Set errno for result underflowing to zero.
	* math/w_atan2f.c: Include <errno.h>.
	(__atan2f): Set errno for result underflowing to zero.
	* math/w_atan2l.c: Include <errno.h>.
	(__atan2l): Set errno for result underflowing to zero.
	* math/auto-libm-test-in: Don't allow missing errno for some atan2
	tests.
	* math/auto-libm-test-out: Regenerated.

1 files changed, 4 insertions, 5 deletions

diff --git a/math/auto-libm-test-in b/math/auto-libm-test-in
index 7ad407c238..420f657d81 100644
--- a/math/auto-libm-test-in
+++ b/math/auto-libm-test-in
@@ -157,13 +157,12 @@ atan2 -min -max
 atan2 min_subnorm -max
 atan2 -min_subnorm -max
 # Bug 15319: underflow exception may be missing.
-# Bug 16349: errno setting may be missing.
 atan2 1 max missing-underflow
 atan2 -1 max missing-underflow
-atan2 min max missing-underflow missing-errno
-atan2 -min max missing-underflow missing-errno
-atan2 min_subnorm max missing-underflow missing-errno
-atan2 -min_subnorm max missing-underflow missing-errno
+atan2 min max missing-underflow
+atan2 -min max missing-underflow
+atan2 min_subnorm max missing-underflow
+atan2 -min_subnorm max missing-underflow
 
 atanh 0
 atanh -0