From aba05ec06bb490d830cb9a17f41de1a4b03607b4 Mon Sep 17 00:00:00 2001
From: khvitaly <khvitaly@gmail.com>
Date: Mon, 12 Apr 2021 21:47:42 +0300
Subject: [PATCH] Prevent mouse dragging from dismissing existing selection

---
 src/cascadia/TerminalControl/TermControl.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/cascadia/TerminalControl/TermControl.cpp b/src/cascadia/TerminalControl/TermControl.cpp
index c8df3a8ab65..5eede743df9 100644
--- a/src/cascadia/TerminalControl/TermControl.cpp
+++ b/src/cascadia/TerminalControl/TermControl.cpp
@@ -1418,6 +1418,13 @@ namespace winrt::Microsoft::Terminal::Control::implementation
                     _selectionNeedsToBeCopied = true;
                 }
 
+                if (_terminal->IsSelectionActive())
+                {
+                    // GH#9787: if selection is active we don't want to track the touchdown position
+                    // so that dragging the mouse will extend the selection rather than starting the new one
+                    _singleClickTouchdownPos = std::nullopt;
+                }
+
                 _renderer->TriggerSelection();
             }
             else if (point.Properties().IsRightButtonPressed())