Bug in base: NSMapGet()

[Daniel Ferreira (theiostream)]

I believe I have found a bug trying out some basic behavior of
NSMapGet(). When running the following program (compiled with clang
and GNUstep's libobjc):

---
#import <Foundation/Foundation.h>

int main() {
        NSPointerFunctionsOptions keyOptions =
NSPointerFunctionsOpaqueMemory | NSPointerFunctionsOpaquePersonality;
        NSPointerFunctionsOptions valueOptions =
NSPointerFunctionsWeakMemory | NSPointerFunctionsObjectPersonality;
        NSMapTable *table = [[NSMapTable alloc]
initWithKeyOptions:keyOptions valueOptions:valueOptions capacity:0];

        printf("%p\n", NSMapGet(table, "xxx"));
        NSMapInsert(table, "xxx", "asdasd");
        printf("%p\n", NSMapGet(table, "xxx"));
        printf("%p\n", NSMapGet(table, "yyy"));

        return 0;
}
---

I get a segfault when trying to get a key that does not exist on the
map table (in this case, 'yyy').

Stacktrace:

#0  objc_msgSend_fpret () at /root/gnustep/libobjc2/objc_msgSend.x86-64.S:130
#1  0x00007ffff7bc5ba4 in autorelease (obj=0x4019df) at
/root/gnustep/libobjc2/arc.m:277
#2  0x00007ffff7bc5fa3 in objc_autorelease (obj=0x4019df) at
/root/gnustep/libobjc2/arc.m:376
#3  0x00007ffff7bc724d in objc_loadWeak (object=0x794b08) at
/root/gnustep/libobjc2/arc.m:693
#4  0x00007ffff75af773 in pointerFunctionsRead (PF=<optimized out>,
addr=<optimized out>) at ././NSConcretePointerFunctions.h:105
#5  GSIMapNodeForKeyInBucket (map=0x78cb20, bucket=0x794ac0, key=...)
at ../Headers/GNUstepBase/GSIMap.h:639
#6  0x00007ffff75acc65 in GSIMapNodeForKey (map=0x78cb20, key=...) at
../Headers/GNUstepBase/GSIMap.h:667
#7  NSMapGet (table=0x78cb20, key=0x4019ea) at NSConcreteMapTable.m:591
#8  0x00000000004009f2 in main ()

I tried investigating the issue and spent some hours trying to get the
internals of NSConcreteMapTable, but after some hours I could come to
no conclusion. Could anyone who played with this try to point me to a
fix?

-- Daniel.