common-main: call restore_sigpipe_to_default()

[thirdparty/git.git] / common-main.c

diff --git a/common-main.c b/common-main.c
index 353c6ea175bba31fb4367f98e970195beb9e2a60..20e55ef7d7681ddda6a29e26d196e484c8720b7a 100644 (file)
--- a/common-main.c
+++ b/common-main.c
@@ -1,6 +1,27 @@
 #include "cache.h"
 #include "exec_cmd.h"
 
+/*
+ * Many parts of Git have subprograms communicate via pipe, expect the
+ * upstream of a pipe to die with SIGPIPE when the downstream of a
+ * pipe does not need to read all that is written.  Some third-party
+ * programs that ignore or block SIGPIPE for their own reason forget
+ * to restore SIGPIPE handling to the default before spawning Git and
+ * break this carefully orchestrated machinery.
+ *
+ * Restore the way SIGPIPE is handled to default, which is what we
+ * expect.
+ */
+static void restore_sigpipe_to_default(void)
+{
+       sigset_t unblock;
+
+       sigemptyset(&unblock);
+       sigaddset(&unblock, SIGPIPE);
+       sigprocmask(SIG_UNBLOCK, &unblock, NULL);
+       signal(SIGPIPE, SIG_DFL);
+}
+
 int main(int argc, char **av)
 {
        /*
@@ -18,5 +39,7 @@ int main(int argc, char **av)
 
        argv[0] = git_extract_argv0_path(argv[0]);
 
+       restore_sigpipe_to_default();
+
        return cmd_main(argc, argv);
 }