Merge pull request #5521 from Tyriar/5314

Add quirks setting to control DECSET/DECRST 12

demo/client/components/window/optionsWindow.ts

@@ -72,6 +72,7 @@ export class OptionsWindow extends BaseWindow implements IControlWindow {
       'linkHandler',
       'logger',
       'overviewRuler',
+      'quirks',
       'theme',
       'windowOptions',
       'windowsPty',

src/common/InputHandler.test.ts

@@ -2341,7 +2341,7 @@ describe('InputHandler', () => {
     });
     it('DEC privates with set/reset semantic', async () => {
       // initially reset
-      const reset = [1, 6, 9, 12, 45, 66, 1000, 1002, 1003, 1004, 1006, 1016, 47, 1047, 1049, 2004, 2026];
+      const reset = [1, 6, 9, 45, 66, 1000, 1002, 1003, 1004, 1006, 1016, 47, 1047, 1049, 2004, 2026];
       for (const mode of reset) {
         await inputHandler.parseP(`\x1b[?${mode}$p`);
         assert.deepEqual(reportStack.pop(), `\x1b[?${mode};2$y`);   // initial reset
@@ -2365,6 +2365,23 @@ describe('InputHandler', () => {
         assert.deepEqual(reportStack.pop(), `\x1b[?${mode};1$y`);   // again set
       }
     });
+    it('DEC privates quirks', async () => {
+      // Cursor blink
+      const mode = 12;
+      await inputHandler.parseP(`\x1b[?${mode}$p`);
+      assert.deepEqual(reportStack.pop(), `\x1b[?${mode};2$y`); // initial reset
+      await inputHandler.parseP(`\x1b[?${mode}h`);
+      await inputHandler.parseP(`\x1b[?${mode}$p`);
+      assert.deepEqual(reportStack.pop(), `\x1b[?${mode};2$y`); // still reset
+
+      optionsService.options.quirks.allowSetCursorBlink = true;
+      await inputHandler.parseP(`\x1b[?${mode}h`);
+      await inputHandler.parseP(`\x1b[?${mode}$p`);
+      assert.deepEqual(reportStack.pop(), `\x1b[?${mode};1$y`); // now active
+      await inputHandler.parseP(`\x1b[?${mode}l`);
+      await inputHandler.parseP(`\x1b[?${mode}$p`);
+      assert.deepEqual(reportStack.pop(), `\x1b[?${mode};2$y`);   // now inactive
+    });
     it('DEC privates perma modes', async () => {
       // [mode number, state value]
       const perma = [[3, 0], [8, 3], [67, 4], [1005, 4], [1015, 4], [1048, 1]];

src/common/InputHandler.ts

@@ -1877,7 +1877,7 @@ export class InputHandler extends Disposable implements IInputHandler {
    * | 7     | Auto-wrap Mode (DECAWM).                                | #Y      |
    * | 8     | Auto-repeat Keys (DECARM). Always on.                   | #N      |
    * | 9     | X10 xterm mouse protocol.                               | #Y      |
-   * | 12    | Start Blinking Cursor.                                  | #Y      |
+   * | 12    | Start Blinking Cursor.                                  | #P[Requires the allowSetCursorBlink quirk option enabled.] |
    * | 25    | Show Cursor (DECTCEM).                                  | #Y      |
    * | 45    | Reverse wrap-around.                                    | #Y      |
    * | 47    | Use Alternate Screen Buffer.                            | #Y      |
@@ -1930,7 +1930,9 @@ export class InputHandler extends Disposable implements IInputHandler {
           this._coreService.decPrivateModes.wraparound = true;
           break;
         case 12:
-          this._optionsService.options.cursorBlink = true;
+          if (this._optionsService.rawOptions.quirks?.allowSetCursorBlink) {
+            this._optionsService.options.cursorBlink = true;
+          }
           break;
         case 45:
           this._coreService.decPrivateModes.reverseWraparound = true;
@@ -2125,7 +2127,7 @@ export class InputHandler extends Disposable implements IInputHandler {
    * | 7     | No Wraparound Mode (DECAWM).                            | #Y      |
    * | 8     | No Auto-repeat Keys (DECARM).                           | #N      |
    * | 9     | Don't send Mouse X & Y on button press.                 | #Y      |
-   * | 12    | Stop Blinking Cursor.                                   | #Y      |
+   * | 12    | Stop Blinking Cursor.                                   | #P[Requires the allowSetCursorBlink quirk option enabled.] |
    * | 25    | Hide Cursor (DECTCEM).                                  | #Y      |
    * | 45    | No reverse wrap-around.                                 | #Y      |
    * | 47    | Use Normal Screen Buffer.                               | #Y      |
@@ -2171,7 +2173,9 @@ export class InputHandler extends Disposable implements IInputHandler {
           this._coreService.decPrivateModes.wraparound = false;
           break;
         case 12:
-          this._optionsService.options.cursorBlink = false;
+          if (this._optionsService.rawOptions.quirks?.allowSetCursorBlink) {
+            this._optionsService.options.cursorBlink = false;
+          }
           break;
         case 45:
           this._coreService.decPrivateModes.reverseWraparound = false;

src/common/services/OptionsService.ts

@@ -53,7 +53,8 @@ export const DEFAULT_OPTIONS: Readonly<Required<ITerminalOptions>> = {
   convertEol: false,
   termName: 'xterm',
   cancelEvents: false,
-  overviewRuler: {}
+  overviewRuler: {},
+  quirks: {}
 };
 
 const FONT_WEIGHT_OPTIONS: Extract<FontWeight, string>[] = ['normal', 'bold', '100', '200', '300', '400', '500', '600', '700', '800', '900'];

src/common/services/Services.ts

@@ -262,6 +262,7 @@ export interface ITerminalOptions {
   windowOptions?: IWindowOptions;
   wordSeparator?: string;
   overviewRuler?: IOverviewRulerOptions;
+  quirks?: ITerminalQuirks;
   scrollOnEraseInDisplay?: boolean;
 
   [key: string]: any;
@@ -300,6 +301,10 @@ export interface ITheme {
   extendedAnsi?: string[];
 }
 
+export interface ITerminalQuirks {
+  allowSetCursorBlink?: boolean;
+}
+
 export const IOscLinkService = createDecorator<IOscLinkService>('OscLinkService');
 export interface IOscLinkService {
   serviceBrand: undefined;

typings/xterm.d.ts

@@ -197,6 +197,12 @@ declare module '@xterm/xterm' {
      */
     minimumContrastRatio?: number;
 
+    /**
+     * Control various quirks features that are either non-standard or standard
+     * in but generally rejected in modern terminals.
+     */
+    quirks?: ITerminalQuirks;
+
     /**
      * Whether to reflow the line containing the cursor when the terminal is
      * resized. Defaults to false, because shells usually handle this
@@ -407,6 +413,21 @@ declare module '@xterm/xterm' {
     extendedAnsi?: string[];
   }
 
+  /**
+   * Control various quirks features that are either non-standard or standard
+   * in but generally rejected in modern terminals.
+   */
+  export interface ITerminalQuirks {
+    /**
+     * Enables support for DECSET 12 and DECRST 12 which controls cursor blink.
+     * Programs such as `vim` may use this to set the cursor blink state but may
+     * not change it back when exiting. Generally the terminal emulator should
+     * be in control of whether the cursor blinks or not and the application in
+     * modern terminals. Note that DECRQM works regardless of this option.
+     */
+    allowSetCursorBlink?: boolean;
+  }
+
   /**
    * Pty information for Windows.
    */