Bug#418019: moon-lander: Moon-lander dies because it can't open background image: "backgrounds/.."

[Christian Aichinger]

Package: moon-lander
Version: 1:1.0-3
Severity: normal
Tags: patch

Hi,
moon-lander starts up for me but dies when I press enter to start to
play:
,-----------------
| [EMAIL PROTECTED] moon-lander
| Sound active
| reading game options in /home/greek0/.moon_lander
| cannot open file for reading: /home/greek0/.moon_lander - loading defaults
| open /dev/sequencer: No such file or directory
| Opened audio at 22050 Hz 16 bit stereoscreen initialized
| Loaded font "/usr/share/games/moon-lander/fonts/ConsoleFont.bmp". Width:6, 
Height:13
| Loaded font "/usr/share/games/moon-lander/fonts/LargeFont.bmp". Width:16, 
Height:18
| Couldn't load /usr/share/games/moon-lander/images/backgrounds/..: Unsupported 
image format
`-----------------

Relevant code paths are in get_new_background():
,-----------------
|     while (!done){
|       if ( files[count] = readdir(dir) ){
|       
|         //printf("I see - %d %s\n", count, files[count]->d_name);
|         count++;
|       }
|       else{
|         done = 1;
|       }
|     
|       if (count > 99) {
|         done = 1;
|       }
|     }
| 
|   /** ... some more code ... **/
| 
|   if (game->back_no < 2){
|     game->back_no = 2;
|   }
| 
|   if (game->back_no >= count){
|     game->back_no = 2;
|   }
`-----------------

readdir() gives back all the directory entries, including "." and
"..". Those are supposed to be filtered out later by the
game->back_no < 2 check. Unfortunately readdir() doesn't give back
"." and ".." as the first 2 entries on my system:
,-----------------
| I see - 0 fingers.jpg
| I see - 1 .
| I see - 2 ..
| I see - 3 earth_moon.jpg
| I see - 4 orange_gas.jpg
| I see - 5 blue_nebula.jpg
| I see - 6 fire_and_planet.jpg
| I see - 7 saturn.jpg
| I see - 8 red_plain.jpg
| I see - 9 glowing_nebula.jpg
`-----------------

So the game tries to open "..", which doesn't work, causing
moon-lander to die.

I've attached a patch fixing this by checking in the while loop if
the dirent return by readdir() corresponds to a directory. If so
it's ignored. The two if's have been changed too, so all available
images are cycled.

Cheers,
Christian Aichinger


-- System Information:
Debian Release: 4.0
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 
'experimental')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/dash
Kernel: Linux 2.6.17.4-vs2.1.1-rc23-iphigenie
Locale: LANG=de_AT.UTF-8, LC_CTYPE=de_AT.UTF-8 (charmap=UTF-8)

Versions of packages moon-lander depends on:
ii  libc6                       2.3.6.ds1-13 GNU C Library: Shared libraries
ii  libsdl-image1.2             1.2.5-3      image loading library for Simple D
ii  libsdl-mixer1.2             1.2.6-2      mixer library for Simple DirectMed
ii  libsdl1.2debian             1.2.11-8     Simple DirectMedia Layer
ii  moon-lander-data            1:1.0-3      Data files (sound, images) for moo

moon-lander recommends no packages.

-- no debconf information

--- moon-lander-1.0.orig/moon_lander.c	2007-03-10 23:07:38.000000000 +0100
+++ moon-lander-1.0/moon_lander.c	2007-03-10 23:14:50.000000000 +0100
@@ -197,6 +197,8 @@
     while (!done){
       if ( files[count] = readdir(dir) ){
       
+	if ( files[count]->d_type & DT_DIR )
+	  continue;
 	//printf("I see - %d %s\n", count, files[count]->d_name);
 	count++;
       }
@@ -222,12 +224,12 @@
 
   game->back_no++;
   
-  if (game->back_no < 2){
-    game->back_no = 2;
+  if (game->back_no < 0){
+    game->back_no = 0;
   }
 
   if (game->back_no >= count){
-    game->back_no = 2;
+    game->back_no = 0;
   }