Adding swaptags patch

patch/include.c

@@ -113,6 +113,9 @@
 #if SWAPFOCUS_PATCH && PERTAG_PATCH
 #include "swapfocus.c"
 #endif
+#if SWAPTAGS_PATCH
+#include "swaptags.c"
+#endif
 #if SWITCHCOL_PATCH
 #include "switchcol.c"
 #endif

patch/include.h

@@ -113,6 +113,9 @@
 #if SWAPFOCUS_PATCH && PERTAG_PATCH
 #include "swapfocus.h"
 #endif
+#if SWAPTAGS_PATCH
+#include "swaptags.h"
+#endif
 #if SWITCHCOL_PATCH
 #include "switchcol.h"
 #endif

patch/swaptags.c

@@ -0,0 +1,22 @@
+void
+swaptags(const Arg *arg)
+{
+   unsigned int newtag = arg->ui & TAGMASK;
+   unsigned int curtag = selmon->tagset[selmon->seltags];
+
+   if (newtag == curtag || !curtag || (curtag & (curtag-1)))
+       return;
+
+   for (Client *c = selmon->clients; c != NULL; c = c->next) {
+       if ((c->tags & newtag) || (c->tags & curtag))
+           c->tags ^= curtag ^ newtag;
+
+       if (!c->tags)
+       		c->tags = newtag;
+   }
+
+   selmon->tagset[selmon->seltags] = newtag;
+
+   focus(NULL);
+   arrange(selmon);
+}

patch/swaptags.h

@@ -0,0 +1 @@
+static void swaptags(const Arg *arg);