Implements color output in GNU Screen sessions (issue 277).

src/gtest.cc

@@ -2592,6 +2592,7 @@ bool ShouldUseColor(bool stdout_is_tty) {
         String::CStringEquals(term, "xterm") ||
         String::CStringEquals(term, "xterm-color") ||
         String::CStringEquals(term, "xterm-256color") ||
+        String::CStringEquals(term, "screen") ||
         String::CStringEquals(term, "linux") ||
         String::CStringEquals(term, "cygwin");
     return stdout_is_tty && term_supports_color;

test/gtest_unittest.cc

@@ -6264,8 +6264,17 @@ TEST(ColoredOutputTest, UsesColorsWhenTermSupportsColors) {
   SetEnv("TERM", "xterm-color");  // TERM supports colors.
   EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
 
+  SetEnv("TERM", "xterm-256color");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "screen");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
   SetEnv("TERM", "linux");  // TERM supports colors.
   EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
+
+  SetEnv("TERM", "cygwin");  // TERM supports colors.
+  EXPECT_TRUE(ShouldUseColor(true));  // Stdout is a TTY.
 #endif  // GTEST_OS_WINDOWS
 }