to reject

x.c

@@ -35,6 +35,7 @@ typedef struct {
 	void (*func)(const Arg *);
 	const Arg arg;
 	uint  release;
+	int  altscrn;  /* 0: don't care, -1: not alt screen, 1: alt screen */
 } MouseShortcut;
 
 typedef struct {
@@ -457,6 +458,7 @@ mouseaction(XEvent *e, uint release)
 	for (ms = mshortcuts; ms < mshortcuts + LEN(mshortcuts); ms++) {
 		if (ms->release == release &&
 		    ms->button == e->xbutton.button &&
+		    (!ms->altscrn || (ms->altscrn == (tisaltscr() ? 1 : -1))) &&
 		    (match(ms->mod, state) ||  /* exact or forced */
 		     match(ms->mod, state & ~forcemousemod))) {
 			ms->func(&(ms->arg));