C Recursion fails

[orionrush]

// Ref https://goo.gl/gvzist

The following recursion fails though it compiles and runs in other environments.

    #include <ctype.h>
    #include <string.h>
    #include <stdio.h>
    #include <unistd.h>

    // Ref:
    //http://qr.ae/TUpcap

    int alpha_length=52;
    char alpha[53] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
    static int count = -1;

    void permutations(char arr[], int arr_length, char prefix[], int places)
    {
            int i;
            int j;
            int plength=strlen(prefix);
            char newprefix[plength + 2]; // could be 1, being conservitive;

            // dont run the whole algorithm just enough to visualise recursion
             if(count > 0)
            {
                    return;  
            }

            if(places==0)
            {
                     printf("%d %s\n", ++count, prefix);
                     return;
            }

            for( i = 0; i < arr_length; i++)
            {
                //Concatenation of currentPrefix + arr[i] = newPrefix
                for(j = 0; j < plength; j++)
                {
                    newprefix[j] = prefix[j];
                }
                newprefix[plength] = arr[i];
                newprefix[plength + 1] = '\0';

                // Recursion
                permutations(arr, arr_length, newprefix, places - 1);
            }
    }

    int main()
    {
            permutations(alpha, alpha_length, "", 2);
            return 0;
    }