[Lemon-devel] Memory corruption when using IterableValueMap on Class derived from lemon Graph

[Bernhard Kausler]

Dear all,

the bug was caused by uninitialized "next" and "prev" fields in struct
IterableValueMapNode (resp. struct IterableIntMapNode) in maps.h.
Please find attached a patch for the lemon-main branch, that fixes the
problem. (The patch is valid for lemon-1.2.1, too).

Best,
Bernhard Kausler


On 22.04.2011 09:57, Bernhard Kausler wrote:
> Dear all,
>
> unfortunately, the user registration on the lemon website is broken and
> I can't use the ticket system. Therefore, I report a bug here.
>
> The following code causes a memory access error.
> - Tested for lemon 1.2.1 and the latest lemon-main sources
> - Doesn't happen for other graph maps like IdMap
>
> ---------- code begin ---------
> #include <lemon/list_graph.h>
> #include <lemon/maps.h>
>
> using namespace lemon;
>
> class MyGraph : public ListDigraph {
> };
>
> int main() {
>   MyGraph derived;
>   IterableValueMap<MyGraph, MyGraph::Node, int> derived_m2(derived);
>
>   derived.addNode();
>
>   return 0;
> }
> ---------- code end -----------
>
> gdb backtrace:
> #0  0x00000000004059a3 in lemon::IterableValueMap<MyGraph,
> lemon::ListDigraphBase::Node, int>::unlace (this=0x7fffffffdcf0,
> key=...) at lemon-main/lemon/maps.h:3098
> #1  0x0000000000405050 in lemon::IterableValueMap<MyGraph,
> lemon::ListDigraphBase::Node, int>::add (this=0x7fffffffdcf0, key=...)
> at lemon-main/lemon/maps.h:3255
> #2  0x00000000004026ab in
> lemon::AlterationNotifier<lemon::DigraphExtender<lemon::ListDigraphBase>, lemon::ListDigraphBase::Node>::add
> (this=0x7fffffffdcc0, item=...) at
> /home/bkausler/loca/include/lemon/bits/alteration_notifier.h:356
> #3  0x00000000004018a7 in
> lemon::DigraphExtender<lemon::ListDigraphBase>::addNode
> (this=0x7fffffffdc80) at
> /home/bkausler/local/include/lemon/bits/graph_extender.h:269
> #4  0x00000000004012c8 in lemon::ListDigraph::addNode
> (this=0x7fffffffdc80) at lemon-main/lemon/list_graph.h:352
> #5  0x0000000000400f54 in main () at inheritance-bug.cpp:15
>
> Best,
> Bernhard Kausler
> _______________________________________________
> Lemon-devel mailing list
> Lemon-devel at lemon.cs.elte.hu
> http://lemon.cs.elte.hu/mailman/listinfo/lemon-devel

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