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Changes between Initial Version and Version 1 of Ticket #41124

initial	v1
1	1	Graphviz uses a check in `lib/vmalloc/features/vmalloc` that is supposed to find out whether `alloca(3)` is internally using `malloc(3)`. To do this, this check provides a custom implementation of `malloc(3)` and assumes that if this implementation is going to be called it was called by `alloca(3)`.
2	2
3		However, this assumption doesn't hold in all cases, e.g. it breaks when having `DYLD_INSERT_LIBRARIES` is set, as is the case for trace mode, because the Mac OS loader `dyld` internally calls `malloc(3)`, causing the check to fail.
	3	However, this assumption doesn't hold in all cases, e.g. it breaks when having `DYLD_INSERT_LIBRARIES` set, as is the case for trace mode, because the Mac OS loader `dyld` internally calls `malloc(3)`, causing the check to fail.
4	4
5	5	The check should instead use a global volatile variable to check whether the current call to `malloc(3)` happened while trying to use `alloca(3)`. The overriden `malloc(3)` should behave like the standard one in all other cases.