Fix a bug in Cvar_RegisterVirtual which was corrupting memory when adding a second...

[xonotic/darkplaces.git] / cvar.c

diff --git a/cvar.c b/cvar.c
index 58562d6b642742e911d879ddc0fdc55dd50af0c4..7936c92356be359c13748eca7afbec3250df8ac2 100644 (file)
--- a/cvar.c
+++ b/cvar.c
@@ -492,46 +492,41 @@ void Cvar_RegisterCallback(cvar_t *variable, void (*callback)(cvar_t *))
        variable->callback = callback;
 }
 
-void Cvar_RegisterAlias(cvar_t *variable, const char *alias )
+void Cvar_RegisterVirtual(cvar_t *variable, const char *name )
 {
        cvar_state_t *cvars = &cvars_all;
        cvar_hash_t *hash;
        int hashindex;
 
-       if(!*alias)
+       if(!*name)
        {
-               Con_Printf("Cvar_RegisterAlias: invalid alias name\n");
+               Con_Printf("Cvar_RegisterVirtual: invalid virtual cvar name\n");
                return;
        }
 
        // check for overlap with a command
-       if (Cmd_Exists(cmd_local, alias))
+       if (Cmd_Exists(cmd_local, name))
        {
-               Con_Printf("Cvar_RegisterAlias: %s is a command\n", alias);
+               Con_Printf("Cvar_RegisterVirtual: %s is a command\n", name);
                return;
        }
 
-       if(Cvar_FindVar(&cvars_all, alias, 0))
+       if(Cvar_FindVar(&cvars_all, name, 0))
        {
-               Con_Printf("Cvar_RegisterAlias: %s is a cvar\n", alias);
+               Con_Printf("Cvar_RegisterVirtual: %s is a cvar\n", name);
                return;
        }
 
-       if(!variable->aliases)
-               variable->aliases = (char **)Z_Malloc(sizeof(char *) * 2); // For NULL terminator
-       else
-               variable->aliases = (char **)Mem_Realloc(zonemempool, variable->aliases, sizeof(char *) * (variable->aliases_size + 1));
-       
-       variable->aliases[variable->aliases_size + 1] = NULL;
-       
-       // Add to it
-       variable->aliases[variable->aliases_size] = (char *)Z_Malloc(strlen(alias) + 1);
-       memcpy(variable->aliases[variable->aliases_size], alias, strlen(alias) + 1);
-       variable->aliases_size++;
+       // Resize the variable->aliases list to have room for another entry and a null terminator.
+       // This zero-pads when resizing, so we don't need to write the NULL terminator manually here.
+       // Also if aliases is NULL this allocates fresh for the correct size, so it's fine to just do this.
+       variable->aliases = (char **)Z_Realloc(variable->aliases, sizeof(char *) * (variable->aliases_size + 2));
+       // Add the new alias, and increment the number of aliases in the list
+       variable->aliases[variable->aliases_size++] = (char *)Z_strdup(name);
 
        // link to head of list in this hash table index
        hash = (cvar_hash_t *)Z_Malloc(sizeof(cvar_hash_t));
-       hashindex = CRC_Block((const unsigned char *)alias, strlen(alias)) % CVAR_HASHSIZE;
+       hashindex = CRC_Block((const unsigned char *)name, strlen(name)) % CVAR_HASHSIZE;
        hash->next = cvars->hashtable[hashindex];
        cvars->hashtable[hashindex] = hash;
        hash->cvar = variable;