From b54c7909bd3f9deca6b0ccee6ca8c715d5d025ea Mon Sep 17 00:00:00 2001
From: Fredrik Fornwall <fredrik@fornwall.net>
Date: Sun, 29 Nov 2015 10:04:50 +0100
Subject: [PATCH] Fix crash with wide character in last column

Ignore wide character outputs instead of crashing when the cursor
is in the last column with autowrap disabled.
---
 .../com/termux/terminal/TerminalEmulator.java | 21 ++++++++++++-------
 .../com/termux/terminal/UnicodeInputTest.java |  8 +++++++
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/app/src/main/java/com/termux/terminal/TerminalEmulator.java b/app/src/main/java/com/termux/terminal/TerminalEmulator.java
index 92de6c96..01a4c4dc 100644
--- a/app/src/main/java/com/termux/terminal/TerminalEmulator.java
+++ b/app/src/main/java/com/termux/terminal/TerminalEmulator.java
@@ -2156,15 +2156,22 @@ public final class TerminalEmulator {
 
 		final boolean autoWrap = isDecsetInternalBitSet(DECSET_BIT_AUTOWRAP);
 		final int displayWidth = WcWidth.width(codePoint);
+		final boolean cursorInLastColumn = mCursorCol == mRightMargin - 1;
 
-		if (autoWrap && (mCursorCol == mRightMargin - 1 && ((mAboutToAutoWrap && displayWidth == 1) || displayWidth == 2))) {
-			mScreen.setLineWrap(mCursorRow);
-			mCursorCol = mLeftMargin;
-			if (mCursorRow + 1 < mBottomMargin) {
-				mCursorRow++;
-			} else {
-				scrollDownOneLine();
+		if (autoWrap) {
+			if (cursorInLastColumn && ((mAboutToAutoWrap && displayWidth == 1) || displayWidth == 2)) {
+				mScreen.setLineWrap(mCursorRow);
+				mCursorCol = mLeftMargin;
+				if (mCursorRow + 1 < mBottomMargin) {
+					mCursorRow++;
+				} else {
+					scrollDownOneLine();
+				}
 			}
+		} else if (cursorInLastColumn && displayWidth == 2) {
+			// The behaviour when a wide character is output with cursor in the last column when
+			// autowrap is disabled is not obvious - it's ignored here.
+			return;
 		}
 
 		if (mInsertMode && displayWidth > 0) {
diff --git a/app/src/test/java/com/termux/terminal/UnicodeInputTest.java b/app/src/test/java/com/termux/terminal/UnicodeInputTest.java
index 49fb7306..ba0bbf07 100644
--- a/app/src/test/java/com/termux/terminal/UnicodeInputTest.java
+++ b/app/src/test/java/com/termux/terminal/UnicodeInputTest.java
@@ -84,4 +84,12 @@ public class UnicodeInputTest extends TerminalTestCase {
 		assertLineIs(0, "\uFFFDY   ");
 	}
 
+	public void testWideCharacterWithoutWrapping() throws Exception {
+		// With wraparound disabled. The behaviour when a wide character is output with cursor in
+		// the last column when autowrap is disabled is not obvious, but we expect the wide
+		// character to be ignored here.
+		withTerminalSized(3, 3).enterString("\033[?7l").enterString("枝枝枝").assertLinesAre("枝 ", "   ", "   ");
+		enterString("a枝").assertLinesAre("枝a", "   ", "   ");
+	}
+
 }