From f6cace5aa2ac6d1c4579b59c8e227f937f785800 Mon Sep 17 00:00:00 2001
From: Ingo Weinhold <ingo_weinhold@gmx.de>
Date: Tue, 23 Feb 2010 15:39:30 +0000
Subject: [PATCH] TermView::Draw(): * Apparently Draw() can be invoked with new
 view bounds in effect before the   FrameResized() hook has been invoked (I
 suppose that's not really kosher).   Since TermView updates the terminal
 dimensions in FrameResized() and relied   on the update rect passed to Draw()
 to translate to positions within the   limits, an on-stack buffer could
 overflow, leading to #2851. Now we clamp   the translated positions to
 terminal size. * Draw the background areas right of the last column and below
 the last row   explicitly instead of drawing an additional non-existing
 partial   character/row.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35587 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/apps/terminal/TermView.cpp | 92 +++++++++++++++++++++-------------
 1 file changed, 58 insertions(+), 34 deletions(-)

diff --git a/src/apps/terminal/TermView.cpp b/src/apps/terminal/TermView.cpp
index 13cb2530c0..7a625e54b1 100644
--- a/src/apps/terminal/TermView.cpp
+++ b/src/apps/terminal/TermView.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009, Haiku, Inc.
+ * Copyright 2001-2010, Haiku, Inc.
  * Copyright 2003-2004 Kian Duffy, myob@users.sourceforge.net
  * Parts Copyright 1998-1999 Kazuho Okui and Takashi Murai.
  * All rights reserved. Distributed under the terms of the MIT license.
@@ -13,7 +13,6 @@
  */
 
 
-
 #include "TermView.h"
 
 #include <ctype.h>
@@ -1090,55 +1089,80 @@ TermView::Draw(BRect updateRect)
 // }
 // }
 
-	int32 x1 = (int32)(updateRect.left) / fFontWidth;
-	int32 x2 = (int32)(updateRect.right) / fFontWidth;
+	int32 x1 = (int32)updateRect.left / fFontWidth;
+	int32 x2 = std::min((int)updateRect.right / fFontWidth, fColumns - 1);
 
 	int32 firstVisible = _LineAt(0);
 	int32 y1 = _LineAt(updateRect.top);
-	int32 y2 = _LineAt(updateRect.bottom);
+	int32 y2 = std::min(_LineAt(updateRect.bottom), (int32)fRows - 1);
 
 //debug_printf("TermView::Draw(): (%ld, %ld) - (%ld, %ld), top: %f, fontHeight: %d, scrollOffset: %f\n",
 //x1, y1, x2, y2, updateRect.top, fFontHeight, fScrollOffset);
 
-	for (int32 j = y1; j <= y2; j++) {
-		int32 k = x1;
-		char buf[fColumns * 4 + 1];
+	// clear the area to the right of the line ends
+	if (y1 <= y2) {
+		float clearLeft = fColumns * fFontWidth;
+		if (clearLeft < updateRect.right) {
+			BRect rect(clearLeft, updateRect.top, updateRect.right,
+				updateRect.bottom);
+			SetHighColor(fTextBackColor);
+			FillRect(rect);
+		}
+	}
 
-		if (fVisibleTextBuffer->IsFullWidthChar(j - firstVisible, k))
-			k--;
+	// clear the area below the last line
+	if (y2 == fRows - 1) {
+		float clearTop = _LineOffset(fRows);
+		if (clearTop < updateRect.bottom) {
+			BRect rect(updateRect.left, clearTop, updateRect.right,
+				updateRect.bottom);
+			SetHighColor(fTextBackColor);
+			FillRect(rect);
+		}
+	}
 
-		if (k < 0)
-			k = 0;
+	// draw the affected line parts
+	if (x1 <= x2) {
+		for (int32 j = y1; j <= y2; j++) {
+			int32 k = x1;
+			char buf[fColumns * 4 + 1];
 
-		for (int32 i = k; i <= x2;) {
-			int32 lastColumn = x2;
-			bool insideSelection = _CheckSelectedRegion(j, i, lastColumn);
-			uint16 attr;
-			int32 count = fVisibleTextBuffer->GetString(j - firstVisible, i,
-				lastColumn, buf, attr);
+			if (fVisibleTextBuffer->IsFullWidthChar(j - firstVisible, k))
+				k--;
+
+			if (k < 0)
+				k = 0;
+
+			for (int32 i = k; i <= x2;) {
+				int32 lastColumn = x2;
+				bool insideSelection = _CheckSelectedRegion(j, i, lastColumn);
+				uint16 attr;
+				int32 count = fVisibleTextBuffer->GetString(j - firstVisible, i,
+					lastColumn, buf, attr);
 
 //debug_printf("  fVisibleTextBuffer->GetString(%ld, %ld, %ld) -> (%ld, \"%.*s\"), selected: %d\n",
 //j - firstVisible, i, lastColumn, count, (int)count, buf, insideSelection);
 
-			if (count == 0) {
-				BRect rect(fFontWidth * i, _LineOffset(j),
-					fFontWidth * (lastColumn + 1) - 1, 0);
-				rect.bottom = rect.top + fFontHeight - 1;
+				if (count == 0) {
+					BRect rect(fFontWidth * i, _LineOffset(j),
+						fFontWidth * (lastColumn + 1) - 1, 0);
+					rect.bottom = rect.top + fFontHeight - 1;
 
-				SetHighColor(insideSelection ? fSelectBackColor
-					: fTextBackColor);
-				FillRect(rect);
+					SetHighColor(insideSelection ? fSelectBackColor
+						: fTextBackColor);
+					FillRect(rect);
 
-				i = lastColumn + 1;
-				continue;
+					i = lastColumn + 1;
+					continue;
+				}
+
+				if (IS_WIDTH(attr))
+					count = 2;
+
+				_DrawLinePart(fFontWidth * i, (int32)_LineOffset(j),
+					attr, buf, count, insideSelection, false, this);
+				i += count;
 			}
-
-			if (IS_WIDTH(attr))
-				count = 2;
-
-			_DrawLinePart(fFontWidth * i, (int32)_LineOffset(j),
-				attr, buf, count, insideSelection, false, this);
-			i += count;
 		}
 	}