bug#38031: 26.3; Trying to invoke the macOS File Open window causes Emacs to crash on macOS Catalina

[Michael Dixon]

Thanks Alan. I might be a little over my head here, as I’m not sure how to apply a patch. I presume I would have to build from source...

On Nov 3, 2019, at 3:39 PM, Alan Third <alan@idiocy.org> wrote:

On Sat, Nov 02, 2019 at 06:19:27AM -0400, Michael Dixon wrote:

On macOS Catalina, if I attempt to open a file using
 * File > Open
 * The toolbar button
 * "Open a File" on the splash screen

Emacs crashes. I am using the Homebrew formula with GUI. I have tried
with other Mac Emacs distributions, such as GNU Emacs for Mac OS X and
the Homebrew emacs-plus formula with the same result.

Here's the part of the macOS crash report that I think is useful:

Application Specific Information:
*** Terminating app due to uncaught exception 'NSObjectNotAvailableException',
reason: 'EmacsSavePanel is not a supported subclass for sandboxing'
abort() called
terminating with uncaught exception of type NSException

That sounds suspiciously like the fact we’ve subclassed the save panel
class means it’s no longer considered ‘safe’ by Cocoa.

I suspect there’s no immediate work‐around other than trying to work
out what about EmacsSavePanel is problematic.

Can you try applying the patch below? I don’t think it’ll fix
anything, but it should at least rule out that it’s something in these
functions that’s causing this.

modified   src/nsfns.m
@@ -3067,25 +3067,25 @@ The position is returned as a cons cell (X . Y) of the
}

@implementation EmacsSavePanel
-- (BOOL)performKeyEquivalent:(NSEvent *)theEvent
-{
-  BOOL ret = handlePanelKeys (self, theEvent);
-  if (! ret)
-    ret = [super performKeyEquivalent:theEvent];
-  return ret;
-}
+// - (BOOL)performKeyEquivalent:(NSEvent *)theEvent
+// {
+//   BOOL ret = handlePanelKeys (self, theEvent);
+//   if (! ret)
+//     ret = [super performKeyEquivalent:theEvent];
+//   return ret;
+// }
@end


@implementation EmacsOpenPanel
-- (BOOL)performKeyEquivalent:(NSEvent *)theEvent
-{
-  // NSOpenPanel inherits NSSavePanel, so passing self is OK.
-  BOOL ret = handlePanelKeys (self, theEvent);
-  if (! ret)
-    ret = [super performKeyEquivalent:theEvent];
-  return ret;
-}
+// - (BOOL)performKeyEquivalent:(NSEvent *)theEvent
+// {
+//   // NSOpenPanel inherits NSSavePanel, so passing self is OK.
+//   BOOL ret = handlePanelKeys (self, theEvent);
+//   if (! ret)
+//     ret = [super performKeyEquivalent:theEvent];
+//   return ret;
+// }
@end

-- 
Alan Third