Prevent getpos queueing mouse commands

My change to allow binding the mouse buttons made getpos
push the mouse commands into a command queue, so when you
were asked for a map location, clicked on it with a mouse,
you'd first get the expected effect, and then (most likely)
immediately traveled there.

Change getpos to clear the commands bound to the mouse buttons,
and restore the binds afterwards.

include/extern.h

@@ -273,6 +273,7 @@ extern int extcmds_match(const char *, int, int **);
 extern const char *key2extcmddesc(uchar);
 extern boolean bind_specialkey(uchar, const char *);
 extern void parseautocomplete(char *, boolean);
+extern void lock_mouse_buttons(boolean);
 extern void reset_commands(boolean);
 extern void update_rest_on_space(void);
 extern void rhack(char *);

src/cmd.c

@@ -4280,6 +4280,24 @@ parseautocomplete(char *autocomplete, boolean condition)
     wait_synch();
 }
 
+/* save&clear the mouse button actions, or restore the saved ones */
+void
+lock_mouse_buttons(boolean savebtns)
+{
+    static const struct ext_func_tab *mousebtn[NUM_MOUSE_BUTTONS] = { 0 };
+    int i;
+
+    if (savebtns) {
+        for (i = 0; i < NUM_MOUSE_BUTTONS; i++) {
+            mousebtn[i] = g.Cmd.mousebtn[i];
+            g.Cmd.mousebtn[i] = NULL;
+        }
+    } else {
+        for (i = 0; i < NUM_MOUSE_BUTTONS; i++)
+            g.Cmd.mousebtn[i] = mousebtn[i];
+    }
+}
+
 /* called at startup and after number_pad is twiddled */
 void
 reset_commands(boolean initial)

src/do_name.c

@@ -751,6 +751,7 @@ getpos(coord *ccp, boolean force, const char *goal)
 #ifdef MAC
     lock_mouse_cursor(TRUE);
 #endif
+    lock_mouse_buttons(TRUE);
     for (;;) {
         if (show_goal_msg) {
             pline("Move cursor to %s:", goal);
@@ -769,7 +770,8 @@ getpos(coord *ccp, boolean force, const char *goal)
                 c = cmdq->key;
             } else {
                 cmdq_clear(CQ_CANNED);
-                return -1;
+                result = -1;
+                goto exitgetpos;
             }
             free(cmdq);
         } else {
@@ -1036,9 +1038,11 @@ getpos(coord *ccp, boolean force, const char *goal)
         curs(WIN_MAP, cx, cy);
         flush_screen(0);
     }
+ exitgetpos:
 #ifdef MAC
     lock_mouse_cursor(FALSE);
 #endif
+    lock_mouse_buttons(FALSE);
     if (msg_given)
         clear_nhwindow(WIN_MESSAGE);
     ccp->x = cx;