Fix segmentation fault when adding + 1 to a null pointer

[tim661811]

Description

While upgrading libosdp from version 2.1.0 to 3.0.8, I encountered a segmentation fault. The fault occurred almost immediately upon entering the __cp_setup function.

Investigation

After analyzing the issue, I traced the problem to the LOG_PRINT macro. Specifically, the error originated in the __logger_log function, where the return value of the strrchr function was not properly handled.

As per the documentation, strrchr returns a pointer to the last occurrence of the specified character, or a null pointer if the character is not found. In this case, the file variable already contained just the filename (not the full file path), meaning no path separator was present. Consequently, strrchr returned a null pointer. Adding 1 to a null pointer caused the segmentation fault.

Fix

I updated the code to handle cases where strrchr returns a null pointer, ensuring the macro doesn't attempt to dereference or manipulate invalid pointers.

[sidcha]

LGTM. Thanks for the fix