Rewrite COOKED_READ_DATA

.github/actions/spelling/expect/alphabet.txt

@@ -21,6 +21,7 @@ BBBBCCCCC
 BBGGRR
 efg
 EFG
+efgh
 EFGh
 KLMNOQQQQQQQQQQ
 QQQQQQQQQQABCDEFGHIJ

.github/actions/spelling/expect/expect.txt

@@ -690,7 +690,7 @@ FSINFOCLASS
 fte
 Ftm
 Fullscreens
-fullwidth
+Fullwidth
 FUNCTIONCALL
 fuzzer
 fuzzmain
@@ -1117,6 +1117,7 @@ MDs
 MEASUREITEM
 megamix
 memallocator
+meme
 MENUCHAR
 MENUCONTROL
 MENUDROPALIGNMENT

src/buffer/out/Row.cpp

@@ -118,10 +118,15 @@ LineRendition ROW::GetLineRendition() const noexcept
     return _lineRendition;
 }
 
-uint16_t ROW::GetLineWidth() const noexcept
+// Returns the index 1 past the last (technically) valid column in the row.
+// The interplay between the old console and newer VT APIs which support line renditions is
+// still unclear so it might be necessary to add two kinds of this function in the future.
+// Console APIs treat the buffer as a large NxM matrix after all.
+til::CoordType ROW::GetLineWidth() const noexcept
 {
     const auto scale = _lineRendition != LineRendition::SingleWidth ? 1 : 0;
-    return _columnCount >> scale;
+    const auto padding = _doubleBytePadded ? 1 : 0;
+    return (_columnCount - padding) >> scale;
 }
 
 // Routine Description:

src/buffer/out/Row.hpp

@@ -106,7 +106,7 @@ class ROW final
     bool WasDoubleBytePadded() const noexcept;
     void SetLineRendition(const LineRendition lineRendition) noexcept;
     LineRendition GetLineRendition() const noexcept;
-    uint16_t GetLineWidth() const noexcept;
+    til::CoordType GetLineWidth() const noexcept;
 
     void Reset(const TextAttribute& attr) noexcept;
     void TransferAttributes(const til::small_rle<TextAttribute, uint16_t, 1>& attr, til::CoordType newWidth);

src/buffer/out/textBuffer.cpp

@@ -457,6 +457,64 @@ size_t TextBuffer::GraphemePrev(const std::wstring_view& chars, size_t position)
     return til::utf16_iterate_prev(chars, position);
 }
 
+// Pretend as if `position` is a regular cursor in the TextBuffer.
+// This function will then pretend as if you pressed the left/right arrow
+// keys `distance` amount of times (negative = left, positive = right).
+til::point TextBuffer::NavigateCursor(til::point position, til::CoordType distance)
+{
+    const til::CoordType maxX = _width - 1;
+    const til::CoordType maxY = _height - 1;
+    auto x = std::clamp(position.x, 0, maxX);
+    auto y = std::clamp(position.y, 0, maxY);
+    auto row = &GetRowByOffset(y);
+
+    if (distance < 0)
+    {
+        do
+        {
+            if (x > 0)
+            {
+                x = row->NavigateToPrevious(x);
+            }
+            else if (y <= 0)
+            {
+                break;
+            }
+            else
+            {
+                --y;
+                row = &GetRowByOffset(y);
+                x = row->GetLineWidth() - 1;
+            }
+        } while (++distance != 0);
+    }
+    else if (distance > 0)
+    {
+        auto rowWidth = row->GetLineWidth();
+
+        do
+        {
+            if (x < rowWidth)
+            {
+                x = row->NavigateToNext(x);
+            }
+            else if (y >= maxY)
+            {
+                break;
+            }
+            else
+            {
+                ++y;
+                row = &GetRowByOffset(y);
+                rowWidth = row->GetLineWidth();
+                x = 0;
+            }
+        } while (--distance != 0);
+    }
+
+    return { x, y };
+}
+
 // This function is intended for writing regular "lines" of text as it'll set the wrap flag on the given row.
 // You can continue calling the function on the same row as long as state.columnEnd < state.columnLimit.
 void TextBuffer::Write(til::CoordType row, const TextAttribute& attributes, RowWriteState& state)

src/buffer/out/textBuffer.hpp

@@ -134,6 +134,8 @@ class TextBuffer final
     static size_t GraphemeNext(const std::wstring_view& chars, size_t position) noexcept;
     static size_t GraphemePrev(const std::wstring_view& chars, size_t position) noexcept;
 
+    til::point NavigateCursor(til::point position, til::CoordType distance);
+
     // Text insertion functions
     void Write(til::CoordType row, const TextAttribute& attributes, RowWriteState& state);
     void FillRect(const til::rect& rect, const std::wstring_view& fill, const TextAttribute& attributes);

src/cascadia/UnitTests_TerminalCore/ConptyRoundtripTests.cpp

@@ -21,7 +21,6 @@
 #include "../host/readDataCooked.hpp"
 #include "../host/output.h"
 #include "../host/_stream.h" // For WriteCharsLegacy
-#include "../host/cmdline.h" // For WC_INTERACTIVE
 #include "test/CommonState.hpp"
 
 #include "../cascadia/TerminalCore/Terminal.hpp"
@@ -3165,20 +3164,6 @@ void ConptyRoundtripTests::NewLinesAtBottomWithBackground()
     verifyBuffer(*termTb, term->_mutableViewport.ToExclusive());
 }
 
-void doWriteCharsLegacy(SCREEN_INFORMATION& screenInfo, const std::wstring_view string, DWORD flags = 0)
-{
-    auto dwNumBytes = string.size() * sizeof(wchar_t);
-    VERIFY_NT_SUCCESS(WriteCharsLegacy(screenInfo,
-                                       string.data(),
-                                       string.data(),
-                                       string.data(),
-                                       &dwNumBytes,
-                                       nullptr,
-                                       screenInfo.GetTextBuffer().GetCursor().GetPosition().x,
-                                       flags,
-                                       nullptr));
-}
-
 void ConptyRoundtripTests::WrapNewLineAtBottom()
 {
     // The actual bug case is
@@ -3220,11 +3205,6 @@ void ConptyRoundtripTests::WrapNewLineAtBottom()
         return;
     }
 
-    // I've tested this with 0x0, 0x4, 0x80, 0x84, and 0-8, and none of these
-    // flags seem to make a difference. So we're just assuming 0 here, so we
-    // don't test a bunch of redundant cases.
-    const auto writeCharsLegacyMode = 0;
-
     // This test was originally written for
     //   https://github.com/microsoft/terminal/issues/5691
     //
@@ -3263,7 +3243,7 @@ void ConptyRoundtripTests::WrapNewLineAtBottom()
         }
         else if (writingMethod == PrintWithWriteCharsLegacy)
         {
-            doWriteCharsLegacy(si, str, writeCharsLegacyMode);
+            WriteCharsLegacy(si, str, false, nullptr);
         }
     };
 
@@ -3421,7 +3401,7 @@ void ConptyRoundtripTests::WrapNewLineAtBottomLikeMSYS()
         }
         else if (writingMethod == PrintWithWriteCharsLegacy)
         {
-            doWriteCharsLegacy(si, str, WC_INTERACTIVE);
+            WriteCharsLegacy(si, str, true, nullptr);
         }
     };