Programming :: Using Realloc Multiple Times / 4th Iteration In The Loop Realloc Fails In Strarray_add?

I have a string problem with a function I am writing and I cant figure it out. I am trying to write unit test which will verify it works as expected. As I need to make use of it elsewhere and obviously robust and correct enough that I can rely on it. Okay first of all I define the following structure

Code:
typedef struct strarray {
int size;
char **elements;
} strarray;
code....

My problem is that upon the 4th iteration in the loop realloc fails in strarray_add. glibc reports invalid next size.