Merge pull request #3860 from Tyriar/3855

Fix column selection issues

addons/xterm-addon-webgl/src/WebglRenderer.ts

@@ -455,8 +455,12 @@ export class WebglRenderer extends Disposable implements IRenderer {
     }
     y -= this._terminal.buffer.active.viewportY;
     if (this._model.selection.columnSelectMode) {
-      return x >= this._model.selection.startCol && y >= this._model.selection.viewportCappedStartRow &&
-        x < this._model.selection.endCol && y < this._model.selection.viewportCappedEndRow;
+      if (this._model.selection.startCol <= this._model.selection.endCol) {
+        return x >= this._model.selection.startCol && y >= this._model.selection.viewportCappedStartRow &&
+          x < this._model.selection.endCol && y <= this._model.selection.viewportCappedEndRow;
+      }
+      return x < this._model.selection.startCol && y >= this._model.selection.viewportCappedStartRow &&
+        x >= this._model.selection.endCol && y <= this._model.selection.viewportCappedEndRow;
     }
     return (y > this._model.selection.viewportStartRow && y < this._model.selection.viewportEndRow) ||
       (this._model.selection.viewportStartRow === this._model.selection.viewportEndRow && y === this._model.selection.viewportStartRow && x >= this._model.selection.startCol && x < this._model.selection.endCol) ||

src/browser/renderer/dom/DomRenderer.ts

@@ -304,8 +304,9 @@ export class DomRenderer extends Disposable implements IRenderer {
     const documentFragment = document.createDocumentFragment();
 
     if (columnSelectMode) {
+      const isXFlipped = start[0] > end[0];
       documentFragment.appendChild(
-        this._createSelectionElement(viewportCappedStartRow, start[0], end[0], viewportCappedEndRow - viewportCappedStartRow + 1)
+        this._createSelectionElement(viewportCappedStartRow, isXFlipped ? end[0] : start[0], isXFlipped ? start[0] : end[0], viewportCappedEndRow - viewportCappedStartRow + 1)
       );
     } else {
       // Draw first row

src/browser/renderer/dom/DomRendererRowFactory.ts

@@ -322,8 +322,12 @@ export class DomRendererRowFactory {
       return false;
     }
     if (this._columnSelectMode) {
-      return x >= start[0] && y >= start[1] &&
-        x < end[0] && y < end[1];
+      if (start[0] <= end[0]) {
+        return x >= start[0] && y >= start[1] &&
+          x < end[0] && y <= end[1];
+      }
+      return x < start[0] && y >= start[1] &&
+        x >= end[0] && y <= end[1];
     }
     return (y > start[1] && y < end[1]) ||
         (start[1] === end[1] && y === start[1] && x >= start[0] && x < end[0]) ||

src/browser/services/SelectionService.ts

@@ -207,8 +207,12 @@ export class SelectionService extends Disposable implements ISelectionService {
         return '';
       }
 
+      // For column selection it's not enough to rely on final selection's swapping of reversed
+      // values, it also needs the x coordinates to swap independently of the y coordinate is needed
+      const startCol = start[0] < end[0] ? start[0] : end[0];
+      const endCol = start[0] < end[0] ? end[0] : start[0];
       for (let i = start[1]; i <= end[1]; i++) {
-        const lineText = buffer.translateBufferLineToString(i, true, start[0], end[0]);
+        const lineText = buffer.translateBufferLineToString(i, true, startCol, endCol);
         result.push(lineText);
       }
     } else {