From 3738a8c8a93405936502db2d2b1aeba2983db029 Mon Sep 17 00:00:00 2001
From: Florian Bruhin <me@the-compiler.org>
Date: Sat, 8 Sep 2018 16:20:58 +0200
Subject: [PATCH] Apply caret mode workarounds correctly

---
 qutebrowser/browser/webengine/webenginetab.py | 15 ++++++++++--
 qutebrowser/javascript/caret.js               | 23 +++++++++++++++----
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/qutebrowser/browser/webengine/webenginetab.py b/qutebrowser/browser/webengine/webenginetab.py
index a5367de82..c307df043 100644
--- a/qutebrowser/browser/webengine/webenginetab.py
+++ b/qutebrowser/browser/webengine/webenginetab.py
@@ -234,6 +234,17 @@ class WebEngineCaret(browsertab.AbstractCaret):
 
     """QtWebEngine implementations related to moving the cursor/selection."""
 
+    def _flags(self):
+        """Get flags to pass to JS."""
+        flags = []
+        if qtutils.version_check('5.7.1', compiled=False):
+            flags.append('filter-prefix')
+        if not qtutils.version_check('5.10', compiled=False):
+            flags.append('end-of-doc-workaround')
+        if utils.is_windows:
+            flags.append('windows')
+        return flags
+
     @pyqtSlot(usertypes.KeyMode)
     def _on_mode_entered(self, mode):
         if mode != usertypes.KeyMode.caret:
@@ -246,8 +257,8 @@ class WebEngineCaret(browsertab.AbstractCaret):
             self._tab.search.clear()
 
         self._tab.run_js_async(
-            javascript.assemble('caret',
-                                'setPlatform', sys.platform, qVersion()))
+            javascript.assemble('caret', 'setFlags', self._flags()))
+
         self._js_call('setInitialCursor', callback=self._selection_cb)
 
     def _selection_cb(self, enabled):
diff --git a/qutebrowser/javascript/caret.js b/qutebrowser/javascript/caret.js
index ecb4f97c8..08d5b7382 100644
--- a/qutebrowser/javascript/caret.js
+++ b/qutebrowser/javascript/caret.js
@@ -788,9 +788,17 @@ window._qutebrowser.caret = (function() {
 
     /**
      * Whether we're running on on old Qt 5.7.1.
+     * There, we need to use -webkit-filter.
      * @type {boolean}
      */
-    CaretBrowsing.isOldQt = null;
+    CaretBrowsing.needsFilterPrefix = null;
+
+    /**
+     * Whether we're running on Qt < 5.10.
+     * There, we need some additional movement workarounds.
+     * @type {boolean}
+     */
+    CaretBrowsing.needsEndOfDocWorkaround = null;
 
     /**
      * Check if a node is a control that normally allows the user to interact
@@ -868,7 +876,7 @@ window._qutebrowser.caret = (function() {
     };
 
     CaretBrowsing.injectCaretStyles = function() {
-        const prefix = CaretBrowsing.isOldQt ? "-webkit-" : "";
+        const prefix = CaretBrowsing.needsFilterPrefix ? "-webkit-" : "";
         const style = `
             .CaretBrowsing_Caret {
               position: absolute;
@@ -1322,9 +1330,11 @@ window._qutebrowser.caret = (function() {
         return CaretBrowsing.selectionEnabled;
     };
 
-    funcs.setPlatform = (platform, qtVersion) => {
-        CaretBrowsing.isWindows = platform.startsWith("win");
-        CaretBrowsing.isOldQt = qtVersion === "5.7.1";
+    funcs.setFlags = (flags) => {
+        CaretBrowsing.isWindows = flags.includes("windows");
+        CaretBrowsing.needsFilterPrefix = flags.includes("filter-prefix");
+        CaretBrowsing.needsEndOfDocWorkaround =
+            flags.includes("end-of-doc-workaround");
     };
 
     funcs.disableCaret = () => {
@@ -1408,6 +1418,9 @@ window._qutebrowser.caret = (function() {
 
     funcs.moveToEndOfDocument = () => {
         CaretBrowsing.move("forward", "documentboundary");
+        if (CaretBrowsing.needsEndOfDocWorkaround) {
+            CaretBrowsing.move("left", "character");
+        }
         CaretBrowsing.finishMove();
     };