diff mercurial/scmutil.py @ 45825:8f07f5a9c3de

worker: raise exception instead of calling sys.exit() with child's code

When a worker process returns an error code, we would call
`sys.exit()` with that exit code on the main process. The `SystemExit`
exception would then get caught in `scmutil.callcatch()`, which would
return that error code. The comment there says "Commands shouldn't
sys.exit directly", which I agree with. This patch changes it so we
raise a specific exception when a worker fails so we can catch
instead. I think that means that `SystemExit` is now always an
internal error.

(I had earlier thought that this call to `sys.exit()` was from within
the child process until Matt Harbison made me look again, so thanks
for that!)

Differential Revision: https://phab.mercurial-scm.org/D9287

--- a/mercurial/scmutil.py	Tue Nov 03 09:56:02 2020 -0800
+++ b/mercurial/scmutil.py	Sat Nov 07 21:50:28 2020 -0800
@@ -219,6 +219,9 @@
         ui.error(_(b"abort: %s\n") % inst.message)
         if inst.hint:
             ui.error(_(b"(%s)\n") % inst.hint)
+    except error.WorkerError as inst:
+        # Don't print a message -- the worker already should have
+        return inst.status_code
     except ImportError as inst:
         ui.error(_(b"abort: %s!\n") % stringutil.forcebytestr(inst))
         m = stringutil.forcebytestr(inst).split()[-1]