From: Ashley 'LadyHavoc' Hale <darkplacesengine@gmail.com>
Date: Sat, 18 Sep 2021 21:32:53 +0000 (-0700)
Subject: Fix a bug in Cvar_RegisterVirtual which was corrupting memory when adding a second... 
X-Git-Url: http://git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=commitdiff_plain;h=7b70abc823ed3391ea31938fbc2188bc2bf45d12;hp=c8551c9a1e2767b4ef4908a9198c8d238e2297d2

Fix a bug in Cvar_RegisterVirtual which was corrupting memory when adding a second alias to a cvar.
---

diff --git a/cvar.c b/cvar.c
index cbe8b0f6..7936c923 100644
--- a/cvar.c
+++ b/cvar.c
@@ -517,17 +517,12 @@ void Cvar_RegisterVirtual(cvar_t *variable, const char *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(name) + 1);
-	memcpy(variable->aliases[variable->aliases_size], name, strlen(name) + 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));