From b42ee0965e7ab931c775af886286a3a34a34705d Mon Sep 17 00:00:00 2001
From: benhormann <benhormann@users.noreply.github.com>
Date: Fri, 29 May 2020 08:07:16 +0100
Subject: [PATCH] [vim] Fix vim-mode-change event being signalled twice

---
 keymap/vim.js    |  2 +-
 test/vim_test.js | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/keymap/vim.js b/keymap/vim.js
index b5be59cc4..bca6d46d7 100644
--- a/keymap/vim.js
+++ b/keymap/vim.js
@@ -3203,7 +3203,7 @@
       vim.visualMode = false;
       vim.visualLine = false;
       vim.visualBlock = false;
-      CodeMirror.signal(cm, "vim-mode-change", {mode: "normal"});
+      if (!vim.insertMode) CodeMirror.signal(cm, "vim-mode-change", {mode: "normal"});
       clearFakeCursor(vim);
     }
 
diff --git a/test/vim_test.js b/test/vim_test.js
index 7adace8e4..71284bdf5 100644
--- a/test/vim_test.js
+++ b/test/vim_test.js
@@ -1153,6 +1153,41 @@ testVim('s_visual_block', function(cm, vim, helpers) {
   eq('1hello{\n  world\n', cm.getValue());
 }, {value: '1234\n5678\nabcdefg\n'});
 
+// Test mode change event. It should only fire once per mode transition.
+testVim('on_mode_change', function(cm, vim, helpers) {
+  var modeHist = [];
+  function callback(arg) {
+    var subMode = arg.subMode ? ':' + arg.subMode : '';
+    modeHist.push(arg.mode + subMode);
+  }
+  helpers.doKeys('<Esc>', '<Esc>');
+  cm.on('vim-mode-change', callback);
+  function test(key, mode) {
+    modeHist.length = 0;
+    helpers.doKeys(key);
+    eq(modeHist.join(';'), mode);
+  }
+  test('v', 'visual');
+  test('c', 'insert');
+  test('<Esc>', 'normal');
+  test('<C-v>', 'visual:blockwise');
+  test('I', 'insert');
+  test('<Esc>', 'normal');
+  test('R', 'replace');
+  test('x', '');
+  test('<C-[>', 'normal');
+  test('v', 'visual');
+  test('V', 'visual:linewise');
+  test('<C-v>', 'visual:blockwise');
+  test('v', 'visual');
+  test('<C-c>', 'normal');
+  test('a', 'insert');
+  test('<Esc>', 'normal');
+  test('v', 'visual');
+  test(':', ''); // Event for Command-line mode not implemented.
+  test('y', 'normal');
+});
+
 // Swapcase commands edit in place and do not modify registers.
 testVim('g~w_repeat', function(cm, vim, helpers) {
   // Assert that dw does delete newline if it should go to the next line, and