[Bug 57928] New: Potential null-pointer-dereference

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=57928

Bug ID: 57928
           Summary: Potential null-pointer-dereference
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: opengl
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 78181
  --> https://bugs.winehq.org/attachment.cgi?id=78181
execution trace

I have found a potential null pointer dereference bug in the project (the
latest version) and would like to report it to the maintainers. Can you please
help me check it? Thank you for your effort and patience!

At line 99 in file `dlls/opengl32/unix_wgl.c`, the function
`get_current_context_ptr` may return NULL.

Then, at line 935 in the same file, the pointer `ptr` receives the return
value, which may be NULL. But `ptr` is dereferenced at line 940 without
checking, which may lead to a null-pointer-dereference bug.

A image showing the execution trace is attached.