Function gz_error

dlib/external/zlib/gzlib.c:579–618

Create an error message in allocated memory and set state->err and state->msg accordingly. Free any previous error message already there. Do not try to free or allocate space if the error is Z_MEM_ERROR (out of memory). Simply save the error message as a static string. If there is an allocation failure constructing the error message, then convert the error to out of memory. */

(state, err, msg)

   allocation failure constructing the error message, then convert the error to
   out of memory. */
void ZLIB_INTERNAL gz_error(state, err, msg)
    gz_statep state;
    int err;
    const char *msg;
{
    /* free previously allocated message and clear */
    if (state->msg != NULL) {
        if (state->err != Z_MEM_ERROR)
            free(state->msg);
        state->msg = NULL;
    }

    /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */
    if (err != Z_OK && err != Z_BUF_ERROR)
        state->x.have = 0;

    /* set error code, and if no message, then done */
    state->err = err;
    if (msg == NULL)
        return;

    /* for an out of memory error, return literal string when requested */
    if (err == Z_MEM_ERROR)
        return;

    /* construct error message with path */
    if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) ==
            NULL) {
        state->err = Z_MEM_ERROR;
        return;
    }
#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
    (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3,
                   "%s%s%s", state->path, ": ", msg);
#else
    strcpy(state->msg, state->path);
    strcat(state->msg, ": ");
    strcat(state->msg, msg);
#endif
}

#ifndef INT_MAX
/* portably return maximum value for an int (when limits.h presumed not