RE: What was the most difficult debug you have ever done?
Once there was a BIG fat bug inside my computer which had claws like ...
kidding.
I recently had to debug an intetioanlly bugged program in a debugging test where a function was being called recursively and the function was creating a string and passing it as an argument to the recursive call.
for creating the string a static global variable( char[]) was being used.
which is a MAJOR bug because imangine there is only one recursion. Inside it the static global char[] was being overwritten. Then that call returned. But in the calling function the char * pointing to the argument it was passed has been corrupted by the recursive call.
the solution was to make it a local char[] in the recursive function so each call would have it's own copy a pointer to which would be passed in any child call. Since it is a child call the pointer would point to a valid location (the local copy of the char [] in it's parent call) till the end of this call and beyond.
this was not the MOST difficult but definitely very tricky.
I would guess the most difficult bugs are forgetting to free allocated memory in a very involved program where it is easy to overlook the error.
