Fix GH-17122: memory leak in regex #17132
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Because the subpattern names are persistent, and the fact that the symbol table destruction is skipped when using fast_shutdown, this means the refcounts will not be updated for the destruction of the arrays that hold the subpattern name keys. To solve this, detect this situation and duplicate the strings.
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Actually a thought just occurred to me. Since the subpattern names are destroyed during mshutdown we could just use zend_string_free instead of zend_string_release and then we don't have to do this dance... |
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@nielsdos If I see this correctly, the subpatterns are actually never freed at runtime. So yes, this sounds like we just don't care about refcounting and can unconditionally release them later. I prefer that. |
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Because the subpattern names are persistent, and the fact that the symbol table destruction is skipped when using fast_shutdown, this means the refcounts will not be updated for the destruction of the arrays that hold the subpattern name keys.
To solve this, detect this situation and duplicate the strings.New solution: see belowAn alternative is always destroying the symbol table, but that changes engine behaviour.