Re: [AD] segfaulting on bad midis + workaround

[Eduard Bloch <edi@xxxxxxxxxx>]

#include <hallo.h>
George Foot wrote on Thu Jun 15, 2000 um 02:22:32PM:

> But your exit isn't very clean. :)  Calling `allegro_exit' is
> not really sensible inside an Allegro routine, so I'm assuming

Of course, it's a dirty way to solve the problem.

> you actually meant to exit the program completely (but maybe
> this isn't what you meant).  Given your patch, I'd expect the

Exactly what I want.

> program to crash fairly soon after that point, if you just

That's possible, I removed the corrupted file and couldn't find one to
test this.

> detecting this error, if it only occurs because of a corrupted
> datafile.  Secondly, even if we should detect this error and do
> something safe, I think the most we should do is return an error
> to the program (and not play the MIDI) and let it handle the

Okay, then even this way, patch attached.

> The demo game doesn't really care whether its music can play.
> If it did, it could check what we put in `allegro_error', and

BTW, some routines seem to be pretty slow in DGA, even slower than in
X-Window-graphics, eg. the fade routines.

Eduard.
-- 
=====================================================================
Eduard Bloch <eb@xxxxxxxxxx>; HP: http://eduard.bloch.com/edecosi
0xEDF008C5(GnuPG): E6EB 98E2 B885 8FF0 6C04  5C1D E106 481E EDF0 08C5
:wq

--- midi.c.orig	Wed Jun 14 14:26:15 2000
+++ midi.c	Sun Jun 18 16:57:31 2000
@@ -1054,7 +1054,14 @@
       running_status = 0;
 
       while (p < end) {                         /* work through data stream */
-	 event = *p; 
+	 if (p != NULL)
+       event = *p; 
+    else {                                      /* a bad thing, unusable
+                                                   midi data*/
+       ustrcpy(allegro_error, get_config_text("MIDI data is corrupted."));
+       return -1;
+    };
+    
 	 if (event & 0x80) {                    /* regular message */
 	    p++;
 	    if ((event != 0xF0) && (event != 0xF7) && (event != 0xFF))