X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/e141f4d4bb6584bfbf13003047a2e48e9a6eab6a..56e92e0bffe6f7d3d6ecb0506280529b0a2fa7bf:/tests/skeletons.at

diff --git a/tests/skeletons.at b/tests/skeletons.at
index f96d13e2..18acbc01 100644
--- a/tests/skeletons.at
+++ b/tests/skeletons.at
@@ -288,3 +288,45 @@ foo.y:1.5-6: fatal error: M4 should exit immediately here
 ]])
 
 AT_CLEANUP
+
+
+## ------------------------------------------------ ##
+## Fatal errors but M4 continues producing output.  ##
+## ------------------------------------------------ ##
+
+# At one time, if Bison encountered a fatal error during M4 processing,
+# Bison failed to drain M4's output pipe.  The result was a SIGPIPE.
+# On some platforms, the default disposition for SIGPIPE is terminate,
+# which was fine.  On others, it's ignore, which caused M4 to report
+# the broken pipe to the user, but we don't want to bother the user with
+# that.
+
+# There is a race condition somewhere.  That is, before the associated
+# fix, running this test group many times in a row would occasionally
+# produce a pass among all the failures.
+
+AT_SETUP([[Fatal errors but M4 continues producing output]])
+
+AT_DATA([[gen-skel.pl]],
+[[use warnings;
+use strict;
+my $M4 = "m4";
+my $DNL = "d"."nl";
+print "${M4}_divert_push(0)$DNL\n";
+print '@output(@,@)', "\n";
+(print "garbage"x10, "\n") for (1..1000);
+print "${M4}_divert_pop(0)\n";
+]])
+AT_CHECK([[perl gen-skel.pl > skel.c || exit 77]])
+
+AT_DATA([[input.y]],
+[[%skeleton "./skel.c"
+%%
+start: ;
+]])
+
+AT_BISON_CHECK([[input.y]], [[1]], [[]],
+[[input.y: fatal error: too many arguments for @output directive in skeleton
+]])
+
+AT_CLEANUP