Re: Crash on app start due to icon

[Fred Kiefer]

Great test code! Could you please file this as a bug report for gcc? I am a bit 
unsure whether the issue is in gcc itself or in libobjc but both are handled in 
the same bug tracking system.

Fred

> Am 08.08.2018 um 00:34 schrieb Josh Freeman <gnustep_lists@twilightedge.com>:
> 
> On Aug 5, 2018, at 5:22 AM, Wolfgang Lux wrote:
> 
>> I finally managed to reproduce the crash, once I've noticed that you are 
>> compiling on a 32-bit OS rather than 64-bits (any reason for not using 
>> 64-bits nowadays?).
> 
>   Good catch, now I'm seeing the crash as well (Ubuntu 16.04.5, 32-bit).
> 
> 
>> Setting a breakpoint on the setApplicationIconImage: and then stepping 
>> through that method I found that the code crashes here:
>> 2385      miniWindowSize = [GSCurrentServer() iconSize];
> 
>   It seems to be a gcc/gobjc compiler/runtime bug: Sending a nil message 
> using a method signature that returns a structure (ex. -[NSView bounds] -> 
> NSRect) results in:
> 1. Garbage values in the returned structure's members (affects: 
> 32-bit/64-bit, debug/non-debug)
> 2. A corrupted stack (affects: 32-bit w/non-debug)
> 
>   Attached are two files:
> - nil_msg_check.m: source for a simple test program, NilMsgCheck, which sends 
> a nil message that returns an NSSize value
> - GNUmakefile: makefile for NilMsgCheck
> 
> -----
> Output from running NilMsgCheck on gcc/gobjc 32-bit non-debug:
> 
> [self nmcZeroSize] returned: {width = 0; height = 0}
> [nil nmcZeroSize] returned: {width = -2.90002e-05; height = 0}
> *** stack smashing detected ***: ./obj/NilMsgCheck terminated
> Aborted (core dumped)
> 
>   (If the nil-message is commented-out (nil_msg_check.m:22), NilMsgCheck 
> exits normally without error)
> 
> ----
> Output from running NilMsgCheck on gcc/gobjc 32-bit debug:
> 
> [self nmcZeroSize] returned: {width = 0; height = 0}
> [nil nmcZeroSize] returned: {width = -2.74035e-05; height = -2.78249e-05}
> 
>   (Exits normally)
> 
> ----
> Output from running NilMsgCheck on clang/objc2 32-bit debug:
> 
> [self nmcZeroSize] returned: {width = 0; height = 0}
> [nil nmcZeroSize] returned: {width = 0; height = 0}
> 
>   (Exits normally, values are correctly zeroed)
> 
> 
> 
> Cheers,
> 
> Josh
> 
> 
> <nil_msg_check.m><GNUmakefile>
> 
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