[B2-devel] SheepShaver commit efa32be9e "Optimize invalidate_cache_range()..." linked to obscure crash

[Josh J. <jj...@gm...>]

Hi,

I've bisected a crash in one of my programs running in SheepShaver to  
this commit:

	commit efa32be9ec44956c77e5001e31bebce151cb2ad6
	Author: gbeauche <>
	Date:   Sat Jul 21 10:25:51 2007 +0000
	
		Optimize invalidate_cache_range() for short ranges.

I applied 7bb230ab "apparently this makes newest SDL happy" to each  
checkout I tested to get SheepShaver to run at all.  This is in Mac  
OS X 10.4 "Tiger" for Intel.

The issue occurs only rarely, with regard to what triggers it, but  
it's 100% reproducible.  To reproduce:

* Launch MacRelix
* Run `git --version`
* cd into a Git repo (I only tried my metamage repo)
* Run `time git status` with git v1.7.6

One of three failure modes occurs:

* SheepShaver exits immediately
* The guest OS hangs and SheepShaver consumes maximum CPU
* The command completes with garbled output, having failed to  
recognize its input

	$ time /git status
	10-102.964309e-3152200othing added.
	0x1.0002400000000p-1023ybe you wanted to say 'git add .'?
	
	real 0.07
	user 0.00
	sys  0.07

No failure occurs with any of the following:

* Don't run `git --version` first
* Run `git status` without `time`
* Use git v1.7.5 instead of v1.7.6
* Use a git binary built with symbolics (i.e. enabled to run in the  
Metrowerks debugger)
* Run in Classic instead of SheepShaver
* Use a SheepShaver built with the optimization reverted

If I cd before running `git --version`, the error message is  
displayed ungarbled (which is still wrong, since the repo isn't empty).

If I use an optimized build instead, I get a different error:

	fatal: bad config value for 'core.repositoryformatversion' in .git/ 
config

Since efa32be9e is at best an optimization and demonstrably causes  
problems, I suggest it be reverted immediately.

Josh