respect scroll margins in CUU/CUD/CPL/CNL; test files

fixtures/escape_sequence_files/t0078-DECSTBM_CPL_CNL.in

@@ -0,0 +1,24 @@
+a
+b
+c
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+e
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+g
+h
+i
+j
+k
+l
+m
+n
+o
+p
+q
+r
+s
+t
+u
+v
+w
+x12

fixtures/escape_sequence_files/t0078-DECSTBM_CPL_CNL.text

@@ -0,0 +1,25 @@
+a
+b
+c
+d
+e
+f
+g
+h
+i
+2
+k
+l
+m
+n
+o
+p
+q
+r
+1
+t
+u
+v
+w
+x
+

fixtures/escape_sequence_files/t0079-DECSTBM_VPR.in

@@ -0,0 +1,24 @@
+a
+b
+c
+d
+e
+f
+g
+h
+i
+j
+k
+l
+m
+n
+o
+p
+q
+r
+s
+t
+u
+v
+w
+x1

fixtures/escape_sequence_files/t0079-DECSTBM_VPR.text

@@ -0,0 +1,25 @@
+a
+b
+c
+d
+e
+f
+g
+h
+i
+j
+k
+l
+m
+n
+o
+p
+q
+r
+s
+t
+u
+v
+w
+x
+1

src/InputHandler.ts

@@ -616,7 +616,13 @@ export class InputHandler extends Disposable implements IInputHandler {
    * Cursor Up Ps Times (default = 1) (CUU).
    */
   public cursorUp(params: IParams): void {
-    this._moveCursor(0, -(params.params[0] || 1));
+    // stop at scrollTop
+    const diffToTop = this._bufferService.buffer.y - this._bufferService.buffer.scrollTop;
+    if (diffToTop >= 0) {
+      this._moveCursor(0, -Math.min(diffToTop, params.params[0] || 1));
+    } else {
+      this._moveCursor(0, -(params.params[0] || 1));
+    }
   }
 
   /**
@@ -624,7 +630,13 @@ export class InputHandler extends Disposable implements IInputHandler {
    * Cursor Down Ps Times (default = 1) (CUD).
    */
   public cursorDown(params: IParams): void {
-    this._moveCursor(0, params.params[0] || 1);
+    // stop at scrollBottom
+    const diffToBottom = this._bufferService.buffer.scrollBottom - this._bufferService.buffer.y;
+    if (diffToBottom >= 0) {
+      this._moveCursor(0, Math.min(diffToBottom, params.params[0] || 1));
+    } else {
+      this._moveCursor(0, params.params[0] || 1);
+    }
   }
 
   /**
@@ -649,7 +661,7 @@ export class InputHandler extends Disposable implements IInputHandler {
    * Other than cursorDown (CUD) also set the cursor to first column.
    */
   public cursorNextLine(params: IParams): void {
-    this._moveCursor(0, params.params[0] || 1);
+    this.cursorDown(params);
     this._bufferService.buffer.x = 0;
   }
 
@@ -659,7 +671,7 @@ export class InputHandler extends Disposable implements IInputHandler {
    * Other than cursorUp (CUU) also set the cursor to first column.
    */
   public cursorPrecedingLine(params: IParams): void {
-    this._moveCursor(0, -(params.params[0] || 1));
+    this.cursorUp(params);
     this._bufferService.buffer.x = 0;
   }
 

src/Terminal2.test.ts

@@ -17,7 +17,6 @@ const ROWS = 25;
 
 const TESTFILES = glob.sync('**/escape_sequence_files/*.in', { cwd: path.join(__dirname, '..')});
 const SKIP_FILES = [
-  't0075-DECSTBM_CUU_CUD.in',
   't0076-DECSTBM_IL_DL.in',   // not working due to lineFeed
   't0077-DECSTBM_quirks.in',
   't0084-CBT.in',