WUtil: Rewrote 'wusergnusteppath' to be more efficient

The first optimisation is to compute only once the path, and then
always re-use the value which did not change anyway.
The second optimisation is to avoid a lot of excessive function
calls, including alloc+free that are not necessary and participate
in memory fragmentation.

WINGs/userdefaults.c

@@ -48,35 +48,34 @@ extern char *WMGetApplicationName();
 
 const char *wusergnusteppath()
 {
+	static const char subdir[] = "/GNUstep";
 	static char *path = NULL;
-	char *gspath;
+	char *gspath, *h;
 	int pathlen;
 
+	if (path)
+		/* Value have been already computed, re-use it */
+		return path;
+
 	gspath = getenv("GNUSTEP_USER_ROOT");
 	if (gspath) {
 		gspath = wexpandpath(gspath);
 		if (gspath) {
-			pathlen = strlen(gspath) + 4;
+			path = gspath;
-			path = wmalloc(pathlen);
+			return path;
-			if (wstrlcpy(path, gspath, pathlen) >= pathlen) {
-				wfree(gspath);
-				return NULL;
-			}
-			wfree(gspath);
-		}
-	} else {
-		char *h = wgethomedir();
-		if (!h)
-			return NULL;
-		pathlen = strlen(h) + 8 /* /GNUstep */ + 1;
-		path = wmalloc(pathlen);
-		if (wstrlcpy(path, h, pathlen) >= pathlen ||
-		    wstrlcat(path, "/GNUstep", pathlen) >= pathlen) {
-			wfree(path);
-			return NULL;
 		}
+		wwarning(_("variable GNUSTEP_USER_ROOT defined with invalid path, not used"));
 	}
 
+	h = wgethomedir();
+	if (!h)
+		return NULL;
+
+	pathlen = strlen(h);
+	path = wmalloc(pathlen + sizeof(subdir));
+	strcpy(path, h);
+	strcpy(path + pathlen, subdir);
+
 	return path;
 }