actually fix this

src/buffer/out/textBuffer.cpp

@@ -1189,6 +1189,8 @@ void TextBuffer::ClearScrollback(const til::CoordType start, const til::CoordTyp
         return;
     }
 
+    ClearMarksInRange(til::point{ 0, 0 }, til::point{ _width, height });
+
     // Our goal is to move the viewport to the absolute start of the underlying memory buffer so that we can
     // MEM_DECOMMIT the remaining memory. _firstRow is used to make the TextBuffer behave like a circular buffer.
     // The start parameter is relative to the _firstRow. The trick to get the content to the absolute start
@@ -1204,8 +1206,6 @@ void TextBuffer::ClearScrollback(const til::CoordType start, const til::CoordTyp
     {
         GetMutableRowByOffset(y).Reset(_initialAttributes);
     }
-
-    ClearMarksInRange(til::point{ 0, height }, til::point{ _width, _height });
 }
 
 // Routine Description:

src/cascadia/TerminalControl/ControlCore.cpp

@@ -2009,93 +2009,98 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         }
         else if (_settings->RepositionCursorWithMouse()) // This is also mode==Char && !shiftEnabled
         {
-            // If we're handling a single left click, without shift pressed, and
-            // outside mouse mode, AND the user has RepositionCursorWithMouse turned
-            // on, let's try to move the cursor.
-            //
-            // We'll only move the cursor if the user has clicked after the last
-            // mark, if there is one. That means the user also needs to set up
-            // shell integration to enable this feature.
-            //
-            // As noted in GH #8573, there's plenty of edge cases with this
-            // approach, but it's good enough to bring value to 90% of use cases.
-            const auto cursorPos{ _terminal->GetCursorPosition() };
+            _repositionCursorWithMouse(terminalPosition);
+        }
+        _updateSelectionUI();
+    }
 
-            // Does the current buffer line have a mark on it?
-            const auto& marks{ _terminal->GetMarkExtents() };
-            if (!marks.empty())
+    void ControlCore::_repositionCursorWithMouse(const til::point terminalPosition)
+    {
+        // If we're handling a single left click, without shift pressed, and
+        // outside mouse mode, AND the user has RepositionCursorWithMouse turned
+        // on, let's try to move the cursor.
+        //
+        // We'll only move the cursor if the user has clicked after the last
+        // mark, if there is one. That means the user also needs to set up
+        // shell integration to enable this feature.
+        //
+        // As noted in GH #8573, there's plenty of edge cases with this
+        // approach, but it's good enough to bring value to 90% of use cases.
+        const auto cursorPos{ _terminal->GetCursorPosition() };
+
+        // Does the current buffer line have a mark on it?
+        const auto& marks{ _terminal->GetMarkExtents() };
+        if (!marks.empty())
+        {
+            const auto& last{ marks.back() };
+            const auto [start, end] = last.GetExtent();
+            const auto bufferSize = _terminal->GetTextBuffer().GetSize();
+            auto lastNonSpace = _terminal->GetTextBuffer().GetLastNonSpaceCharacter();
+            bufferSize.IncrementInBounds(lastNonSpace, true);
+
+            // If the user clicked off to the right side of the prompt, we
+            // want to send keystrokes to the last character in the prompt +1.
+            //
+            // We don't want to send too many here. In CMD, if the user's
+            // last command is longer than what they've currently typed, and
+            // they press right arrow at the end of the prompt, COOKED_READ
+            // will fill in characters from the previous command.
+            //
+            // By only sending keypresses to the end of the command + 1, we
+            // should leave the cursor at the very end of the prompt,
+            // without adding any characters from a previous command.
+
+            // terminalPosition is viewport-relative.
+            const auto bufferPos = _terminal->GetViewport().Origin() + terminalPosition;
+            if (bufferPos.y > lastNonSpace.y)
             {
-                const auto& last{ marks.back() };
-                const auto [start, end] = last.GetExtent();
-                const auto bufferSize = _terminal->GetTextBuffer().GetSize();
-                auto lastNonSpace = _terminal->GetTextBuffer().GetLastNonSpaceCharacter();
-                bufferSize.IncrementInBounds(lastNonSpace, true);
+                // Clicked under the prompt. Bail.
+                return;
+            }
 
-                // If the user clicked off to the right side of the prompt, we
-                // want to send keystrokes to the last character in the prompt +1.
-                //
-                // We don't want to send too many here. In CMD, if the user's
-                // last command is longer than what they've currently typed, and
-                // they press right arrow at the end of the prompt, COOKED_READ
-                // will fill in characters from the previous command.
-                //
-                // By only sending keypresses to the end of the command + 1, we
-                // should leave the cursor at the very end of the prompt,
-                // without adding any characters from a previous command.
+            // Limit the click to 1 past the last character on the last line.
+            const auto clampedClick = std::min(bufferPos, lastNonSpace);
 
-                // terminalPosition is viewport-relative.
-                const auto bufferPos = _terminal->GetViewport().Origin() + terminalPosition;
-                if (bufferPos.y > lastNonSpace.y)
+            if (clampedClick >= last.end)
+            {
+                // Get the distance between the cursor and the click, in cells.
+
+                // First, make sure to iterate from the first point to the
+                // second. The user may have clicked _earlier_ in the
+                // buffer!
+                auto goRight = clampedClick > cursorPos;
+                const auto startPoint = goRight ? cursorPos : clampedClick;
+                const auto endPoint = goRight ? clampedClick : cursorPos;
+
+                const auto delta = _terminal->GetTextBuffer().GetCellDistance(startPoint, endPoint);
+                const WORD key = goRight ? VK_RIGHT : VK_LEFT;
+
+                std::wstring buffer;
+                const auto append = [&](TerminalInput::OutputType&& out) {
+                    if (out)
+                    {
+                        buffer.append(std::move(*out));
+                    }
+                };
+
+                // Send an up and a down once per cell. This won't
+                // accurately handle wide characters, or continuation
+                // prompts, or cases where a single escape character in the
+                // command (e.g. ^[) takes up two cells.
+                for (size_t i = 0u; i < delta; i++)
                 {
-                    // Clicked under the prompt. Bail.
-                    return;
+                    append(_terminal->SendKeyEvent(key, 0, {}, true));
+                    append(_terminal->SendKeyEvent(key, 0, {}, false));
                 }
 
-                // Limit the click to 1 past the last character on the last line.
-                const auto clampedClick = std::min(bufferPos, lastNonSpace);
-
-                if (clampedClick >= end)
                 {
-                    // Get the distance between the cursor and the click, in cells.
-
-                    // First, make sure to iterate from the first point to the
-                    // second. The user may have clicked _earlier_ in the
-                    // buffer!
-                    auto goRight = clampedClick > cursorPos;
-                    const auto startPoint = goRight ? cursorPos : clampedClick;
-                    const auto endPoint = goRight ? clampedClick : cursorPos;
-
-                    const auto delta = _terminal->GetTextBuffer().GetCellDistance(startPoint, endPoint);
-                    const WORD key = goRight ? VK_RIGHT : VK_LEFT;
-
-                    std::wstring buffer;
-                    const auto append = [&](TerminalInput::OutputType&& out) {
-                        if (out)
-                        {
-                            buffer.append(std::move(*out));
-                        }
-                    };
-
-                    // Send an up and a down once per cell. This won't
-                    // accurately handle wide characters, or continuation
-                    // prompts, or cases where a single escape character in the
-                    // command (e.g. ^[) takes up two cells.
-                    for (size_t i = 0u; i < delta; i++)
-                    {
-                        append(_terminal->SendKeyEvent(key, 0, {}, true));
-                        append(_terminal->SendKeyEvent(key, 0, {}, false));
-                    }
-
-                    {
-                        // Sending input requires that we're unlocked, because
-                        // writing the input pipe may block indefinitely.
-                        const auto suspension = _terminal->SuspendLock();
-                        _sendInputToConnection(buffer);
-                    }
+                    // Sending input requires that we're unlocked, because
+                    // writing the input pipe may block indefinitely.
+                    const auto suspension = _terminal->SuspendLock();
+                    _sendInputToConnection(buffer);
                 }
             }
         }
-        _updateSelectionUI();
     }
 
     // Method Description:

src/cascadia/TerminalControl/ControlCore.h

@@ -403,6 +403,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void _focusChanged(bool focused);
 
         void _selectSpan(til::point_span s);
+        void _repositionCursorWithMouse(const til::point terminalPosition);
 
         void _contextMenuSelectMark(
             const til::point& pos,

src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp

@@ -239,12 +239,14 @@ class TerminalCoreUnitTests::ConptyRoundtripTests final
     TEST_METHOD(MultilinePromptRegions);
     TEST_METHOD(ManyMultilinePromptsWithTrailingSpaces);
     TEST_METHOD(ReflowPromptRegions);
+    TEST_METHOD(ClearMarksTest);
 
 private:
     bool _writeCallback(const char* const pch, const size_t cch);
     void _flushFirstFrame();
     void _resizeConpty(const til::CoordType sx, const til::CoordType sy);
     void _clearConpty();
+    void _clear(int clearBufferMethod, SCREEN_INFORMATION& si);
 
     [[nodiscard]] std::tuple<TextBuffer*, TextBuffer*> _performResize(const til::size newSize);
 
@@ -2720,9 +2722,6 @@ void ConptyRoundtripTests::ClsAndClearHostClearsScrollbackTest()
     BEGIN_TEST_METHOD_PROPERTIES()
         TEST_METHOD_PROPERTY(L"Data:clearBufferMethod", L"{0, 1, 2}")
     END_TEST_METHOD_PROPERTIES();
-    constexpr auto ClearLikeCls = 0;
-    constexpr auto ClearLikeClearHost = 1;
-    constexpr auto ClearWithVT = 2;
     INIT_TEST_PROPERTY(int, clearBufferMethod, L"Controls whether we clear the buffer like cmd or like powershell");
 
     Log::Comment(L"This test checks the shims for cmd.exe and powershell.exe. "
@@ -2789,6 +2788,31 @@ void ConptyRoundtripTests::ClsAndClearHostClearsScrollbackTest()
     VERIFY_ARE_EQUAL(si.GetViewport().Dimensions(), si.GetBufferSize().Dimensions());
     VERIFY_ARE_EQUAL(si.GetViewport(), si.GetBufferSize());
 
+    _clear(clearBufferMethod, si);
+
+    VERIFY_ARE_EQUAL(si.GetViewport().Dimensions(), si.GetBufferSize().Dimensions());
+    VERIFY_ARE_EQUAL(si.GetViewport(), si.GetBufferSize());
+
+    Log::Comment(L"Painting the frame");
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+
+    Log::Comment(L"========== Checking the host buffer state (after) ==========");
+    verifyBuffer(*hostTb, si.GetViewport().ToExclusive(), true);
+
+    Log::Comment(L"Painting the frame");
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+    Log::Comment(L"========== Checking the terminal buffer state (after) ==========");
+    verifyBuffer(*termTb, term->_mutableViewport.ToExclusive(), true);
+}
+
+void ConptyRoundtripTests::_clear(int clearBufferMethod, SCREEN_INFORMATION& si)
+{
+    constexpr auto ClearLikeCls = 0;
+    constexpr auto ClearLikeClearHost = 1;
+    constexpr auto ClearWithVT = 2;
+
+    auto& sm = si.GetStateMachine();
+
     if (clearBufferMethod == ClearLikeCls)
     {
         // Execute the cls, EXACTLY LIKE CMD.
@@ -2840,20 +2864,6 @@ void ConptyRoundtripTests::ClsAndClearHostClearsScrollbackTest()
 
         sm.ProcessString(L"\x1b[3J");
     }
-
-    VERIFY_ARE_EQUAL(si.GetViewport().Dimensions(), si.GetBufferSize().Dimensions());
-    VERIFY_ARE_EQUAL(si.GetViewport(), si.GetBufferSize());
-
-    Log::Comment(L"Painting the frame");
-    VERIFY_SUCCEEDED(renderer.PaintFrame());
-
-    Log::Comment(L"========== Checking the host buffer state (after) ==========");
-    verifyBuffer(*hostTb, si.GetViewport().ToExclusive(), true);
-
-    Log::Comment(L"Painting the frame");
-    VERIFY_SUCCEEDED(renderer.PaintFrame());
-    Log::Comment(L"========== Checking the terminal buffer state (after) ==========");
-    verifyBuffer(*termTb, term->_mutableViewport.ToExclusive(), true);
 }
 
 void ConptyRoundtripTests::TestResizeWithCookedRead()
@@ -4945,3 +4955,98 @@ void ConptyRoundtripTests::ReflowPromptRegions()
     Log::Comment(L"========== Checking the terminal buffer state (after) ==========");
     verifyBuffer(*termTb, term->_mutableViewport.ToExclusive(), true, true);
 }
+
+void ConptyRoundtripTests::ClearMarksTest()
+{
+    BEGIN_TEST_METHOD_PROPERTIES()
+        TEST_METHOD_PROPERTY(L"Data:clearBufferMethod", L"{0, 1, 2}")
+    END_TEST_METHOD_PROPERTIES();
+
+    INIT_TEST_PROPERTY(int, clearBufferMethod, L"Controls whether we clear the buffer like cmd or like powershell");
+
+    Log::Comment(L"This test checks the shims for cmd.exe and powershell.exe. "
+                 L"Their build in commands for clearing the console buffer "
+                 L"should work to clear the terminal buffer, not just the "
+                 L"terminal viewport.");
+
+    auto& g = ServiceLocator::LocateGlobals();
+    auto& renderer = *g.pRender;
+    auto& gci = g.getConsoleInformation();
+    auto& si = gci.GetActiveOutputBuffer();
+    auto* hostTb = &si.GetTextBuffer();
+    auto* termTb = term->_mainBuffer.get();
+
+    auto& sm = si.GetStateMachine();
+
+    _flushFirstFrame();
+
+    _checkConptyOutput = false;
+    _logConpty = false;
+
+    const auto hostView = si.GetViewport();
+    const auto end = 2 * hostView.Height();
+
+    auto writePrompt = [](StateMachine& stateMachine, const auto& path) {
+        // A prompt looks like:
+        // `PWSH C:\> `
+        //
+        // which is 10 characters for "C:\"
+        stateMachine.ProcessString(FTCS_D);
+        stateMachine.ProcessString(FTCS_A);
+        stateMachine.ProcessString(L"\x1b]9;9;");
+        stateMachine.ProcessString(path);
+        stateMachine.ProcessString(L"\x7");
+        stateMachine.ProcessString(L"PWSH ");
+        stateMachine.ProcessString(path);
+        stateMachine.ProcessString(L"> ");
+        stateMachine.ProcessString(FTCS_B);
+    };
+    auto writeCommand = [](StateMachine& stateMachine, const auto& cmd) {
+        stateMachine.ProcessString(cmd);
+        stateMachine.ProcessString(FTCS_C);
+        stateMachine.ProcessString(L"\r\n");
+    };
+
+    for (auto i = 0; i < end; i++)
+    {
+        writePrompt(sm, L"C:\\");
+        writeCommand(sm, L"Foo-bar");
+        sm.ProcessString(L"This is some text     \r\n");
+    }
+    writePrompt(sm, L"C:\\");
+
+    auto verifyBuffer = [&](const TextBuffer& tb, const til::rect& /*viewport*/, const bool afterClear = false) {
+        const WEX::TestExecution::DisableVerifyExceptions disableExceptionsScope;
+        const auto marks = tb.GetMarkExtents();
+        if (afterClear)
+        {
+            VERIFY_ARE_EQUAL(0u, marks.size());
+        }
+        else
+        {
+            VERIFY_IS_GREATER_THAN(marks.size(), 1u, L"There should be at least one mark");
+        }
+    };
+
+    Log::Comment(L"========== Checking the host buffer state (before) ==========");
+    verifyBuffer(*hostTb, si.GetViewport().ToExclusive());
+
+    Log::Comment(L"Painting the frame");
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+
+    Log::Comment(L"========== Checking the terminal buffer state (before) ==========");
+    verifyBuffer(*termTb, term->_mutableViewport.ToExclusive());
+
+    VERIFY_ARE_EQUAL(si.GetViewport().Dimensions(), si.GetBufferSize().Dimensions());
+    VERIFY_ARE_EQUAL(si.GetViewport(), si.GetBufferSize());
+
+    _clear(clearBufferMethod, si);
+
+    VERIFY_ARE_EQUAL(si.GetViewport().Dimensions(), si.GetBufferSize().Dimensions());
+    VERIFY_ARE_EQUAL(si.GetViewport(), si.GetBufferSize());
+
+    Log::Comment(L"Painting the frame");
+    VERIFY_SUCCEEDED(renderer.PaintFrame());
+    Log::Comment(L"========== Checking the terminal buffer state (after) ==========");
+    verifyBuffer(*termTb, term->_mutableViewport.ToExclusive(), true);
+}

src/terminal/adapter/adaptDispatch.cpp

@@ -3294,10 +3294,6 @@ bool AdaptDispatch::_EraseAll()
     // Also reset the line rendition for the erased rows.
     textBuffer.ResetLineRenditionRange(newViewportTop, newViewportBottom);
 
-    // Clear any marks that remain below the start of the
-    textBuffer.ClearMarksInRange(til::point{ 0, newViewportTop },
-                                 til::point{ bufferSize.Width(), bufferSize.Height() });
-
     // GH#5683 - If this succeeded, but we're in a conpty, return `false` to
     // make the state machine propagate this ED sequence to the connected
     // terminal application. While we're in conpty mode, when the client