From 2e4fac61d2b6ec488bc476230655baaa12fc394e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ingo=20B=C3=BCrk?= <ingo.buerk@tngtech.com>
Date: Tue, 31 Mar 2015 20:47:22 +0200
Subject: [PATCH] Only mark a window if only one window is matched

We only support unique marks, so looping over all matched windows must be prevented.
If more than one window is matched, we reject it with an error message.

fixes #1614
---
 src/commands.c | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/src/commands.c b/src/commands.c
index dc60e974..79071d6b 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -1043,32 +1043,34 @@ void cmd_workspace_name(I3_CMD, char *name) {
 void cmd_mark(I3_CMD, char *mark, char *toggle) {
     HANDLE_EMPTY_MATCH;
 
-    owindow *current;
-    TAILQ_FOREACH(current, &owindows, owindows) {
-        DLOG("matching: %p / %s\n", current->con, current->con->name);
-        current->con->mark_changed = true;
-        if (toggle != NULL && current->con->mark && strcmp(current->con->mark, mark) == 0) {
-            DLOG("removing window mark %s\n", mark);
-            FREE(current->con->mark);
-        } else {
-            DLOG("marking window with str %s\n", mark);
-            FREE(current->con->mark);
-            current->con->mark = sstrdup(mark);
-        }
+    owindow *current = TAILQ_FIRST(&owindows);
+    if (current == NULL) {
+        ysuccess(false);
+        return;
+    }
+
+    /* Marks must be unique, i.e., no two windows must have the same mark. */
+    if (current != TAILQ_LAST(&owindows, owindows_head)) {
+        yerror("A mark must not be put onto more than one window");
+        return;
+    }
+
+    DLOG("matching: %p / %s\n", current->con, current->con->name);
+    current->con->mark_changed = true;
+    if (toggle != NULL && current->con->mark && strcmp(current->con->mark, mark) == 0) {
+        DLOG("removing window mark %s\n", mark);
+        FREE(current->con->mark);
+    } else {
+        DLOG("marking window with str %s\n", mark);
+        FREE(current->con->mark);
+        current->con->mark = sstrdup(mark);
     }
 
     DLOG("Clearing all non-matched windows with this mark\n");
     Con *con;
     TAILQ_FOREACH(con, &all_cons, all_cons) {
-        /* Skip matched windows, we took care of them already. */
-        bool matched = false;
-        TAILQ_FOREACH(current, &owindows, owindows) {
-            if (current->con == con) {
-                matched = true;
-                break;
-            }
-        }
-        if (matched)
+        /* Skip matched window, we took care of it already. */
+        if (current->con == con)
             continue;
 
         if (con->mark && strcmp(con->mark, mark) == 0) {