[AD] Missing ASSERTs

[Bob <ohannessian@xxxxxxxxxx>]

Just found that exists() and file_exists() have no ASSERTs to check if I
passed NULL or not as argument. Turns out it crashed VC. Well, here's
the patch for it.

C:\DJGPP\> patch -p0 < file.diff


--

- Robert J Ohannessian

--- /cvs/allegro/src/file.c	Sat Jul 29 06:18:44 2000
+++ allegro/src/file.c	Mon Dec 11 13:58:40 2000
@@ -651,6 +651,7 @@
 int file_exists(AL_CONST char *filename, int attrib, int *aret)
 {
    int a;
+   ASSERT(filename);
 
    if (ustrchr(filename, '#')) {
       PACKFILE *f = pack_fopen_special_file(filename, F_READ);
@@ -683,6 +684,7 @@
  */
 int exists(AL_CONST char *filename)
 {
+   ASSERT(filename);
    return file_exists(filename, FA_ARCH | FA_RDONLY, NULL);
 }