fix #370 : Can't correctly undo/redo "Delete current line".

NEWS.md

@@ -114,6 +114,7 @@ Red Panda C++ Version 2.27
   - enhancement: Support "extern template" in code parser.
   - enhancement: Set shortcuts for tools menu item.
   - enhancement: Enhancement for custom tools.
+  - fix: Can't correctly undo/redo "Delete current line".
     
 Red Panda C++ Version 2.26
   - enhancement: Code suggestion for embedded std::vectors.

libs/qsynedit/qsynedit/qsynedit.cpp

@@ -1964,7 +1964,8 @@ void QSynEdit::doDeleteFromBOL()
 
 void QSynEdit::doDeleteLine()
 {
-    if (!mReadOnly && (mDocument->count() > 0)) {
+    if (mReadOnly || (mDocument->count() <= 0))
+        return;
     PCodeFoldingRange foldRange=foldStartAtLine(mCaretY);
     if (foldRange && foldRange->collapsed)
         return;
@@ -1973,37 +1974,30 @@ void QSynEdit::doDeleteLine()
     addSelectionToUndo();
     if (selAvail())
         setBlockBegin(caretXY());
-        QStringList helper(lineText());
+    int oldCaretY = caretY();
-        if (mCaretY == mDocument->count()) {
+    bool isLastLine = (oldCaretY >= mDocument->count());
-            if (mDocument->count()==1) {
+    bool isFirstLine = (oldCaretY == 1);
-                mDocument->putLine(mCaretY - 1,"");
+    BufferCoord startPos;
-                mUndoList->addChange(ChangeReason::Delete,
+    BufferCoord endPos;
-                                     BufferCoord{1, mCaretY},
+    if (isLastLine) {
-                                     BufferCoord{helper.length() + 1, mCaretY},
+        if (isFirstLine) {
-                                     helper, SelectionMode::Normal);
+            startPos.ch = 1;
+            startPos.line = oldCaretY;
         } else {
-                QString s = mDocument->getLine(mCaretY-2);
+            startPos.ch = mDocument->getLine(oldCaretY-2).length()+1;
-                mDocument->deleteAt(mCaretY - 1);
+            startPos.line = oldCaretY-1;
-                helper.insert(0,"");
-                mUndoList->addChange(ChangeReason::Delete,
-                                     BufferCoord{s.length()+1, mCaretY-1},
-                                     BufferCoord{helper.length() + 1, mCaretY},
-                                     helper, SelectionMode::Normal);
-                doLinesDeleted(mCaretY, 1);
-                mCaretY--;
         }
+        endPos.ch = lineText().length()+1;
+        endPos.line = oldCaretY;
     } else {
-            mDocument->deleteAt(mCaretY - 1);
+        startPos.ch = 1;
-            helper.append("");
+        startPos.line = oldCaretY;
-            mUndoList->addChange(ChangeReason::Delete,
+        endPos.ch = 1;
-                                 BufferCoord{1, mCaretY},
+        endPos.line = oldCaretY+1;
-                                 BufferCoord{helper.length() + 1, mCaretY},
-                                 helper, SelectionMode::Normal);
-            doLinesDeleted(mCaretY, 1);
     }
+    doDeleteText(startPos, endPos, SelectionMode::Normal);
     endEditing();
-        internalSetCaretXY(BufferCoord{1, mCaretY}); // like seen in the Delphi editor
+    internalSetCaretXY(BufferCoord{1, oldCaretY});
-    }
 }
 
 void QSynEdit::doSelectLine()