From 1a3846161a6fc58f45cb5b13aa93bc73d6112341 Mon Sep 17 00:00:00 2001
From: Paris <paris@sourcelair.com>
Date: Mon, 30 May 2016 17:11:31 +0300
Subject: [PATCH] Proper rendering of inverse data in default colors

Fix #57
---
 src/xterm.js | 59 +++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 42 insertions(+), 17 deletions(-)

diff --git a/src/xterm.js b/src/xterm.js
index 6bec2030..608f88b9 100644
--- a/src/xterm.js
+++ b/src/xterm.js
@@ -968,6 +968,17 @@
     };
 
 
+    /**
+     * Flags used to render terminal text properly
+     */
+    Terminal.flags = {
+      BOLD: 0b00001,
+      UNDERLINE: 0b00010,
+      BLINK: 0b00100,
+      INVERSE: 0b01000,
+      INVISIBLE: 0b10000
+    }
+
     /*
      * Rendering Engine
      *
@@ -1035,8 +1046,7 @@
                 fg = (data >> 9) & 0x1ff;
                 flags = data >> 18;
 
-                // bold
-                if (flags & 1) {
+                if (flags & Terminal.flags.BOLD) {
                   if (!Terminal.brokenBold) {
                     out += ' xterm-bold ';
                   }
@@ -1044,35 +1054,50 @@
                   if (fg < 8) fg += 8;
                 }
 
-                // underline
-                if (flags & 2) {
+                if (flags & Terminal.flags.UNDERLINE) {
                   out += ' xterm-underline ';
                 }
 
-                // blink
-                if (flags & 4) {
+                if (flags & Terminal.flags.BLINK) {
                     out += ' xterm-blink ';
                 }
 
-                // inverse
-                if (flags & 8) {
-                  bg = (data >> 9) & 0x1ff;
-                  fg = data & 0x1ff;
-                  // Should inverse just be before the
-                  // above boldColors effect instead?
-                  if ((flags & 1) && fg < 8) fg += 8;
+                /**
+                 * If inverse flag is on, then swap the foreground and background variables.
+                 */
+                if (flags & Terminal.flags.INVERSE) {
+                    /* One-line variable swap in JavaScript: http://stackoverflow.com/a/16201730 */
+                    bg = [fg, fg = bg][0];
+                    // Should inverse just be before the
+                    // above boldColors effect instead?
+                    if ((flags & 1) && fg < 8) fg += 8;
                 }
 
-                // invisible
-                if (flags & 16) {
+                if (flags & Terminal.flags.INVISIBLE) {
                   out += ' xterm-hidden ';
                 }
 
-                if (bg !== 256) {
+                /**
+                 * Weird situation: Invert flag used black foreground and white background results
+                 * in invalid background color, positioned at the 256 index of the 256 terminal
+                 * color map. Pin the colors manually in such a case.
+                 *
+                 * Source: https://github.com/sourcelair/xterm.js/issues/57
+                 */
+                if (flags & Terminal.flags.INVERSE) {
+                  if (bg == 257) {
+                    bg = 15;
+                  }
+                  if (fg == 256) {
+                    fg = 0;
+                  }
+                }
+
+                if (bg < 256) {
                   out += ' xterm-bg-color-' + bg + ' ';
                 }
 
-                if (fg !== 257) {
+                if (fg < 256) {
                   out += ' xterm-color-' + fg + ' ';
                 }