From 6d550f3cdbca6091042526a0153e0db18192447e Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Wed, 1 Oct 2025 09:24:02 +0800
Subject: [PATCH] test(terminal/mouse_spec): forwarding works with resized grid
 (#35969)

---
 src/nvim/plines.c                       |  7 ++-
 test/functional/terminal/mouse_spec.lua | 83 ++++++++++++++++++++++++-
 2 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/src/nvim/plines.c b/src/nvim/plines.c
index b1d5daf5d9..655a0ee002 100644
--- a/src/nvim/plines.c
+++ b/src/nvim/plines.c
@@ -930,8 +930,9 @@ int plines_m_win(win_T *wp, linenr_T first, linenr_T last, int max)
   return MIN(max, count);
 }
 
-/// Return number of window lines a physical line range will occupy.
-/// Only considers real and filler lines.
+/// Return total number of physical and filler lines in a physical line range.
+/// Doesn't treat a fold as a single line or consider a wrapped line multiple lines,
+/// unlike plines_m_win() or win_text_height().
 ///
 /// Mainly used for calculating scrolling offsets.
 int plines_m_win_fill(win_T *wp, linenr_T first, linenr_T last)
@@ -940,7 +941,7 @@ int plines_m_win_fill(win_T *wp, linenr_T first, linenr_T last)
 
   if (diffopt_filler()) {
     for (int lnum = first; lnum <= last; lnum++) {
-      // Note: this also considers folds.
+      // Note: this also considers folds (no filler lines inside folds).
       int n = diff_check_fill(wp, lnum);
       count += MAX(n, 0);
     }
diff --git a/test/functional/terminal/mouse_spec.lua b/test/functional/terminal/mouse_spec.lua
index 86c58d5ab5..3dc68e394a 100644
--- a/test/functional/terminal/mouse_spec.lua
+++ b/test/functional/terminal/mouse_spec.lua
@@ -99,7 +99,7 @@ describe(':terminal mouse', function()
 
     describe('with mouse events enabled by the program', function()
       before_each(function()
-        tt.enable_mouse()
+        tt.enable_mouse() -- FIXME: this doesn't work on Windows?
         tt.feed_data('mouse enabled\n')
         screen:expect([[
           line27                                            |
@@ -381,6 +381,87 @@ describe(':terminal mouse', function()
                                                             |
         ]])
       end)
+
+      it('mouse forwarding works with resized grid', function()
+        skip(is_os('win'))
+
+        screen:detach()
+        local Screen = require('test.functional.ui.screen')
+        screen = Screen.new(50, 7, { ext_multigrid = true })
+        screen:expect([[
+        ## grid 1
+          [2:--------------------------------------------------]|*6
+          [3:--------------------------------------------------]|
+        ## grid 2
+          line27                                            |
+          line28                                            |
+          line29                                            |
+          line30                                            |
+          mouse enabled                                     |
+          ^                                                  |
+        ## grid 3
+          {5:-- TERMINAL --}                                    |
+        ]])
+
+        screen:try_resize_grid(2, 58, 11)
+        screen:expect({ any = vim.pesc('rows: 11, cols: 58') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 0, 0)
+        screen:expect({ any = vim.pesc('"!!^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 0, 0)
+        screen:expect({ any = vim.pesc('#!!^') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 10, 0)
+        screen:expect({ any = vim.pesc('"!+^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 10, 0)
+        screen:expect({ any = vim.pesc('#!+^') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 0, 57)
+        screen:expect({ any = vim.pesc('"Z!^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 0, 57)
+        screen:expect({ any = vim.pesc('#Z!^') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 10, 57)
+        screen:expect({ any = vim.pesc('"Z+^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 10, 57)
+        screen:expect({ any = vim.pesc('#Z+^') })
+
+        command('setlocal winbar=WINBAR')
+        screen:expect({ any = vim.pesc(('{5:WINBAR%s}'):format((' '):rep(52))) })
+        eq('t', api.nvim_get_mode().mode)
+
+        api.nvim_input_mouse('right', 'press', '', 2, 0, 0)
+        eq('nt', api.nvim_get_mode().mode)
+        api.nvim_input_mouse('right', 'release', '', 2, 0, 0)
+        feed('i')
+        eq('t', api.nvim_get_mode().mode)
+
+        api.nvim_input_mouse('right', 'press', '', 2, 0, 57)
+        eq('nt', api.nvim_get_mode().mode)
+        api.nvim_input_mouse('right', 'release', '', 2, 0, 57)
+        feed('i')
+        eq('t', api.nvim_get_mode().mode)
+
+        api.nvim_input_mouse('right', 'press', '', 2, 1, 0)
+        screen:expect({ any = vim.pesc('"!!^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 1, 0)
+        screen:expect({ any = vim.pesc('#!!^') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 10, 0)
+        screen:expect({ any = vim.pesc('"!*^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 10, 0)
+        screen:expect({ any = vim.pesc('#!*^') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 1, 57)
+        screen:expect({ any = vim.pesc('"Z!^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 1, 57)
+        screen:expect({ any = vim.pesc('#Z!^') })
+
+        api.nvim_input_mouse('right', 'press', '', 2, 10, 57)
+        screen:expect({ any = vim.pesc('"Z*^') })
+        api.nvim_input_mouse('right', 'release', '', 2, 10, 57)
+        screen:expect({ any = vim.pesc('#Z*^') })
+      end)
     end)
 
     describe('with a split window and other buffer', function()