[gcc r11-1128] gcc-changelog: Use non-zero exit status on error

[Jonathan Wakely]

https://gcc.gnu.org/g:62963c60fc19d07615afe9d4f1b897b2f60801b2

commit r11-1128-g62963c60fc19d07615afe9d4f1b897b2f60801b2
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Jun 9 20:39:39 2020 +0100

    gcc-changelog: Use non-zero exit status on error
    
    Also add comment explaining what the script does.
    
    contrib/ChangeLog:
    
            * gcc-changelog/git_email.py: Set exit status on error.

Diff:
---
 contrib/gcc-changelog/git_email.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/contrib/gcc-changelog/git_email.py b/contrib/gcc-changelog/git_email.py
index 367cf76d8ee..bf74bd8b156 100755
--- a/contrib/gcc-changelog/git_email.py
+++ b/contrib/gcc-changelog/git_email.py
@@ -70,6 +70,9 @@ class GitEmail(GitCommit):
                          strict=strict)
 
 
+# With zero arguments, process every patch file in the ./patches directory.
+# With one argument, process the named patch file.
+# Patch files must be in 'git format-patch' format.
 if __name__ == '__main__':
     if len(sys.argv) == 1:
         allfiles = []
@@ -100,3 +103,4 @@ if __name__ == '__main__':
             if not email.lines:
                 print('Error: patch contains no parsed lines', file=sys.stderr)
             email.print_errors()
+            sys.exit(1)