range checks for buffer iterator

src/Buffer.test.ts

@@ -3,7 +3,7 @@
  * @license MIT
  */
 
-import { assert } from 'chai';
+import { assert, expect } from 'chai';
 import { ITerminal } from './Types';
 import { Buffer, DEFAULT_ATTR, CHAR_DATA_CHAR_INDEX } from './Buffer';
 import { CircularList } from './common/CircularList';
@@ -514,4 +514,35 @@ describe('Buffer', () => {
       }
     });
   });
+  describe('BufferStringIterator', function(): void {
+    it('iterator does not ovrflow buffer limits', function(): void {
+      const terminal = new TestTerminal({rows: 5, cols: 10, scrollback: 5});
+      const data = [
+        'aaaaaaaaaa',
+        'aaaaaaaaa\n',
+        'aaaaaaaaaa',
+        'aaaaaaaaa\n',
+        'aaaaaaaaaa',
+        'aaaaaaaaaa',
+        'aaaaaaaaaa',
+        'aaaaaaaaa\n',
+        'aaaaaaaaaa',
+        'aaaaaaaaaa'
+      ];
+      terminal.writeSync(data.join(''));
+      // brute force test with insane values
+      expect(() => {
+        for (let overscan = 0; overscan < 20; ++overscan) {
+          for (let start = -10; start < 20; ++start) {
+            for (let end = -10; end < 20; ++end) {
+              const it = terminal.buffer.iterator(false, start, end, overscan, overscan);
+              while (it.hasNext()) {
+                it.next();
+              }
+            }
+          }
+        }
+      }).to.not.throw();
+    });
+  });
 });

src/Buffer.ts

@@ -424,6 +424,12 @@ export class BufferStringIterator implements IBufferStringIterator {
     private _startOverscan: number = 0,
     private _endOverscan: number = 0
   ) {
+    if (this._startIndex < 0) {
+      this._startIndex = 0;
+    }
+    if (this._endIndex > this._buffer.lines.length) {
+      this._endIndex = this._buffer.lines.length;
+    }
     this._current = this._startIndex;
   }
 
@@ -433,12 +439,16 @@ export class BufferStringIterator implements IBufferStringIterator {
 
   public next(): IBufferStringIteratorResult {
     const range = this._buffer.getWrappedRangeForLine(this._current);
+    // limit search window to overscan value at both borders
     if (range.first < this._startIndex - this._startOverscan) {
       range.first = this._startIndex - this._startOverscan;
     }
     if (range.last > this._endIndex + this._endOverscan) {
       range.last = this._endIndex + this._endOverscan;
     }
+    // limit to current buffer length
+    range.first = Math.max(range.first, 0);
+    range.last = Math.min(range.last, this._buffer.lines.length);
     let result = '';
     for (let i = range.first; i <= range.last; ++i) {
       // TODO: always apply trimRight after fixing #1685

src/Linkifier.ts

@@ -262,7 +262,6 @@ export class Linkifier extends EventEmitter implements ILinkifier {
       x2 = this._terminal.cols;
       y2--;
     }
-    console.log(x1, y1, x2, y2);
 
     this._mouseZoneManager.add(new MouseZone(
       x1 + 1,