Negative base function

/* The ipow() function is a function I wrote to return the power of an integer without needing a cast
 * The buf_update() function puts the generated digits into a buffer and keeps track of the pointers
 * for said buffer. Getting the input from the terminal and getting the values back from the buffer
 * are handled with separate functions that don't have much to do with this code and that I know work.
 * The functions that have declarations here are the only ones this function depends on         */

void connegbase(int n, int r)
{
    /*
     * Gives 1  1  8  70  1 for digit values which is obviously wrong
     * for -124 converting to base -10
     */

    /* Takes the number to be converted n, and the base to convert to r */
    static int  e = 0, e_flg = false;
    int     m;

    /* These functions are not the problem */
    int     ipow(int n, int e);
    void    buf_update(int n);

    /* Find the minimum power of r whose absolute value is greater than |n| */
    while ( !e_flg &&
        abs(ipow(r, e++)) < abs(n)) {
    ;
    }
    e_flg = true;   /* So above loop doesn't execute again */

    /* Find minimum multiplicator of |r^e| that is > |n| */
    for (m = 0; m * abs(ipow(r, e)) < abs(n); ++m) {
    ;
    }
    buf_update(m);
    if (e && n) {
    /* | m * r^e - |n| | passed as n */
    connegbase(abs(m * ipow(r, --e)) - abs(n), r);
    }
    e_flg = false;  /* Reset for next invocation */
    return;
}