When generating the texture name lookup hash table, add new entries to

the end of chains. This way, entries earlier in the texture list trump
later entries with the same name.
This fixes a bug with the wrong sky being shown in Spooky01.wad (thanks
Porsche Monty).

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 2172

1 files changed, 17 insertions, 3 deletions

diff --git a/src/r_data.c b/src/r_data.c
index d03becd5..ccfc5efe 100644
--- a/src/r_data.c
+++ b/src/r_data.c
@@ -413,6 +413,7 @@ R_GetColumn
 
 static void GenerateTextureHashTable(void)
 {
+    texture_t **rover;
     int i;
     int key;
 
@@ -429,12 +430,25 @@ static void GenerateTextureHashTable(void)
 
         textures[i]->index = i;
 
-        // Hook into hash table
+        // Vanilla Doom does a linear search of the texures array
+        // and stops at the first entry it finds.  If there are two
+        // entries with the same name, the first one in the array
+        // wins. The new entry must therefore be added at the end
+        // of the hash chain, so that earlier entries win.
 
         key = W_LumpNameHash(textures[i]->name) % numtextures;
 
-        textures[i]->next = textures_hashtable[key];
-        textures_hashtable[key] = textures[i];
+        rover = &textures_hashtable[key];
+
+        while (*rover != NULL)
+        {
+            rover = &(*rover)->next;
+        }
+
+        // Hook into hash table
+
+        textures[i]->next = NULL;
+        *rover = textures[i];
     }
 }