[.bashrc] Stop find_up if directory does not exist

.bashrc

@@ -45,12 +45,17 @@ fi
 # des infos quand on est dans un dépôt versionné
 
 find_up () {
+    local path normalized_path normalized_ret
     path="$1"
     shift 1
-    while [[ "`readlink -f -- \"$path\"`" != "/" ]];
+    normalized_path=`readlink -f -- "$path"`
+    normalized_ret=$?
+    while [[ "$normalized_path" != "/" ]] && [ $normalized_ret -eq 0 ];
     do
         find "$path"  -maxdepth 1 -mindepth 1 "$@"
         path=${path}/..
+        normalized_path=`readlink -f -- "$path"`
+        normalized_ret=$?
     done
 }