fix(terminal): handle horizontal scrolling in another window (#24828)

3 files changed, 63 insertions, 23 deletions

diff --git a/src/nvim/mouse.c b/src/nvim/mouse.c
index 176aff849e..0f77b5d568 100644
--- a/src/nvim/mouse.c
+++ b/src/nvim/mouse.c
@@ -1003,13 +1003,13 @@ void ins_mouse(int c)
 ///    K_MOUSERIGHT - MSCR_RIGHT
 /// "curwin" may have been changed to the window that should be scrolled and
 /// differ from the window that actually has focus.
-static void do_mousescroll(cmdarg_T *cap)
+void do_mousescroll(cmdarg_T *cap)
 {
   bool shift_or_ctrl = mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL);
 
   if (cap->arg == MSCR_UP || cap->arg == MSCR_DOWN) {
     // Vertical scrolling
-    if (!(State & MODE_INSERT) && shift_or_ctrl) {
+    if ((State & MODE_NORMAL) && shift_or_ctrl) {
       // whole page up or down
       (void)onepage(cap->arg ? FORWARD : BACKWARD, 1);
     } else {
diff --git a/src/nvim/terminal.c b/src/nvim/terminal.c
index a7e810087a..2d21451c9d 100644
--- a/src/nvim/terminal.c
+++ b/src/nvim/terminal.c
@@ -79,6 +79,7 @@
 #include "nvim/move.h"
 #include "nvim/msgpack_rpc/channel_defs.h"
 #include "nvim/normal.h"
+#include "nvim/ops.h"
 #include "nvim/option.h"
 #include "nvim/optionstr.h"
 #include "nvim/pos.h"
@@ -1456,18 +1457,38 @@ static bool send_mouse_event(Terminal *term, int c)
     return false;
   }
 
-  if (c == K_MOUSEDOWN || c == K_MOUSEUP) {
+  if (c == K_MOUSEUP || c == K_MOUSEDOWN || c == K_MOUSELEFT || c == K_MOUSERIGHT) {
     win_T *save_curwin = curwin;
     // switch window/buffer to perform the scroll
     curwin = mouse_win;
     curbuf = curwin->w_buffer;
-    int direction = c == K_MOUSEDOWN ? MSCR_DOWN : MSCR_UP;
-    if (mod_mask & (MOD_MASK_SHIFT | MOD_MASK_CTRL)) {
-      scroll_redraw(direction, curwin->w_botline - curwin->w_topline);
-    } else if (p_mousescroll_vert > 0) {
-      scroll_redraw(direction, (linenr_T)p_mousescroll_vert);
+
+    cmdarg_T cap;
+    oparg_T oa;
+    CLEAR_FIELD(cap);
+    clear_oparg(&oa);
+    cap.oap = &oa;
+
+    switch (cap.cmdchar = c) {
+    case K_MOUSEUP:
+      cap.arg = MSCR_UP;
+      break;
+    case K_MOUSEDOWN:
+      cap.arg = MSCR_DOWN;
+      break;
+    case K_MOUSELEFT:
+      cap.arg = MSCR_LEFT;
+      break;
+    case K_MOUSERIGHT:
+      cap.arg = MSCR_RIGHT;
+      break;
+    default:
+      abort();
     }
 
+    // Call the common mouse scroll function shared with other modes.
+    do_mousescroll(&cap);
+
     curwin->w_redr_status = true;
     curwin = save_curwin;
     curbuf = curwin->w_buffer;
diff --git a/test/functional/terminal/mouse_spec.lua b/test/functional/terminal/mouse_spec.lua
index a2e9ffa1d7..6dccd14994 100644
--- a/test/functional/terminal/mouse_spec.lua
+++ b/test/functional/terminal/mouse_spec.lua
@@ -287,7 +287,7 @@ describe(':terminal mouse', function()
         ]])
       end)
 
-      it("won't lose focus if another window is scrolled", function()
+      it("scrolling another window keeps focus and respects 'mousescroll'", function()
         feed('<ScrollWheelUp><4,0><ScrollWheelUp><4,0>')
         screen:expect([[
           {7: 21 }line                 │line30                  |
@@ -308,20 +308,6 @@ describe(':terminal mouse', function()
           ==========                ==========              |
           {3:-- TERMINAL --}                                    |
         ]])
-      end)
-
-      it("scrolling another window respects 'mousescroll'", function()
-        command('set mousescroll=ver:1')
-        feed('<ScrollWheelUp><4,0>')
-        screen:expect([[
-          {7: 26 }line                 │line30                  |
-          {7: 27 }line                 │rows: 5, cols: 25       |
-          {7: 28 }line                 │rows: 5, cols: 24       |
-          {7: 29 }line                 │mouse enabled           |
-          {7: 30 }line                 │{1: }                       |
-          ==========                ==========              |
-          {3:-- TERMINAL --}                                    |
-        ]])
         command('set mousescroll=ver:10')
         feed('<ScrollWheelUp><4,0>')
         screen:expect([[
@@ -336,6 +322,39 @@ describe(':terminal mouse', function()
         command('set mousescroll=ver:0')
         feed('<ScrollWheelUp><4,0>')
         screen:expect_unchanged()
+        feed([[<C-\><C-N><C-W>w]])
+        command('setlocal nowrap')
+        feed('0<C-V>gg3ly$4p<C-W>wi')
+        screen:expect([[
+          {7:  1 }linelinelinelineline │line30                  |
+          {7:  2 }linelinelinelineline │rows: 5, cols: 25       |
+          {7:  3 }linelinelinelineline │rows: 5, cols: 24       |
+          {7:  4 }linelinelinelineline │mouse enabled           |
+          {7:  5 }linelinelinelineline │{1: }                       |
+          ==========                ==========              |
+          {3:-- TERMINAL --}                                    |
+        ]])
+        feed('<ScrollWheelRight><4,0>')
+        screen:expect([[
+          {7:  1 }nelinelineline       │line30                  |
+          {7:  2 }nelinelineline       │rows: 5, cols: 25       |
+          {7:  3 }nelinelineline       │rows: 5, cols: 24       |
+          {7:  4 }nelinelineline       │mouse enabled           |
+          {7:  5 }nelinelineline       │{1: }                       |
+          ==========                ==========              |
+          {3:-- TERMINAL --}                                    |
+        ]])
+        command('set mousescroll=hor:4')
+        feed('<ScrollWheelLeft><4,0>')
+        screen:expect([[
+          {7:  1 }nelinelinelineline   │line30                  |
+          {7:  2 }nelinelinelineline   │rows: 5, cols: 25       |
+          {7:  3 }nelinelinelineline   │rows: 5, cols: 24       |
+          {7:  4 }nelinelinelineline   │mouse enabled           |
+          {7:  5 }nelinelinelineline   │{1: }                       |
+          ==========                ==========              |
+          {3:-- TERMINAL --}                                    |
+        ]])
       end)
 
       it('will lose focus if another window is clicked', function()