curses mouse right-click

Right button is button3 rather than button2.  Accept either and treat
both as "not left" to pass CLICK_2 back to the core.

Treat <Ctrl>+left-click as "not left" too, to simplify usage with Mac
one-button mouse (where <Ctrl>+left-click can be configured to send
"secondary click" but might not be set do so) or one-button laptop
trackpad (where having two fingers on the scrolling portion of the pad
while clicking the button is necessary to send "secondary click").

win/curses/cursinit.c

@@ -838,8 +838,10 @@ curses_init_options()
 
 #ifdef NCURSES_MOUSE_VERSION
     if (iflags.wc_mouse_support) {
-        mousemask(BUTTON1_CLICKED, NULL);
+        curses_mouse_support(iflags.wc_mouse_support);
     }
+#else
+    iflags.wc_mouse_support = 0;
 #endif
 }
 

win/curses/cursmisc.c

@@ -870,6 +870,13 @@ curses_convert_keys(int key)
     return ret;
 }
 
+/* we treat buttons 2 and 3 as equivalent so that it doesn't matter which
+   one is for right-click and which for middle-click; the core uses CLICK_2
+   for right-click ("not left" click) even though 2 might be middle button;
+   we also support Ctrl+left-click as another way to get "not left" click
+   since Mac is traditionally saddled with a one button mouse or trackpad */
+#define MOUSEBUTTONS ((BUTTON1_CLICKED | BUTTON2_CLICKED | BUTTON3_CLICKED) \
+                      | BUTTON_CTRL)
 
 /* Process mouse events.  Mouse movement is processed until no further
 mouse movement events are available.  Returns 0 for a mouse click
@@ -884,8 +891,8 @@ curses_get_mouse(int *mousex, int *mousey, int *mod)
 #ifdef NCURSES_MOUSE_VERSION
     MEVENT event;
 
-    if (getmouse(&event) == OK) { /* When the user clicks left mouse button */
+    if (getmouse(&event) == OK) { /* True if user has clicked */
-        if (event.bstate & (BUTTON1_CLICKED | BUTTON2_CLICKED)) {
+        if ((event.bstate & MOUSEBUTTONS) != 0) {
         /*
          * The ncurses man page documents wmouse_trafo() incorrectly.
          * It says that last argument 'TRUE' translates from screen
@@ -903,17 +910,16 @@ curses_get_mouse(int *mousex, int *mousey, int *mod)
          * or the ncurses documentation, so keep the 'bad' argument for
          * it until we find out.  [Mouse can be used successfully with
          * 'bad' coordinate translation via align_message:bottom (and
-         * avoiding align_status:left) so that the subset of the screen
+         * avoiding align_status:top or left) so that the subset of the
-         * corresponding to the map needs no translation.  Adding instead
+         * screen corresponding to the map needs no translation.  Adding
-         * of subtracting or vice versa makes no difference when amount
+         * instead of subtracting makes no difference when amount is 0.]
-         * involved is 0.]
          */
                              TRUE
 #else
                              FALSE
 #endif
                              )) {
-                key = 0;        /* Flag mouse click */
+                key = '\0'; /* core uses this to detect a mouse click */
                 *mousex = event.x + 1; /* +1: screen 0..78 is map 1..79 */
                 *mousey = event.y;
 
@@ -922,7 +928,8 @@ curses_get_mouse(int *mousex, int *mousey, int *mod)
                     (*mousey)--;
                 }
 
-                *mod = (event.bstate & BUTTON1_CLICKED) ? CLICK_1 : CLICK_2;
+                *mod = ((event.bstate & (BUTTON1_CLICKED | BUTTON_CTRL))
+                        == BUTTON1_CLICKED) ? CLICK_1 : CLICK_2;
             }
         }
     }
@@ -941,7 +948,7 @@ int mode; /* 0: off, 1: on, 2: alternate on */
     if (!mode)
         newmask = 0;
     else
-        newmask = BUTTON1_CLICKED | BUTTON2_CLICKED;
+        newmask = MOUSEBUTTONS; /* buttons 1, 2, and 3 */
 
     result = mousemask(newmask, &oldmask);
     nhUse(result);