Escape more characters for GN shell writing.

tools/gn/escape_unittest.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/escape.h"
 
 TEST(Escape, Ninja) {
   EscapeOptions opts;
   opts.mode = ESCAPE_NINJA;
   std::string result = EscapeString("asdf: \"$\\bar", opts, NULL);
   EXPECT_EQ("asdf$:$ \"$$\\bar", result);
 }
 
 TEST(Escape, Shell) {
   EscapeOptions opts;
   opts.mode = ESCAPE_SHELL;
   std::string result = EscapeString("asdf: \"$\\bar", opts, NULL);
 #if defined(OS_WIN)
   // Windows shell doesn't escape backslashes, but it does backslash-escape
   // quotes.
-  EXPECT_EQ("\"asdf: \\\"$\\bar\"", result);
+  EXPECT_EQ("\"asdf: \\\"\\$\\bar\"", result);
 #else
-  EXPECT_EQ("\"asdf: \\\"$\\\\bar\"", result);
+  EXPECT_EQ("\"asdf: \\\"\\$\\\\bar\"", result);
 #endif
+
+  // Some more generic shell chars.
+  result = EscapeString("a_;<*b", opts, NULL);
+  EXPECT_EQ("a_\\;\\<\\*b", result);
+}
+
+TEST(Escape, NinjaShell) {
+  EscapeOptions opts;
+  opts.mode = ESCAPE_NINJA_SHELL;
+
+  // When escaping for Ninja and the shell, we would escape a $, then escape
+  // the backslash again.
+  std::string result = EscapeString("a$b", opts, NULL);
+  EXPECT_EQ("a\\$$b", result);
 }
 
 TEST(Escape, UsedQuotes) {
   EscapeOptions shell_options;
   shell_options.mode = ESCAPE_SHELL;
 
   EscapeOptions ninja_options;
   ninja_options.mode = ESCAPE_NINJA;
 
   EscapeOptions ninja_shell_options;
@@ skipping 21 matching lines @@
   // Ninja escaping shouldn't use quoting.
   used_quotes = false;
   EXPECT_EQ("foo$ bar", EscapeString("foo bar", ninja_options, &used_quotes));
   EXPECT_FALSE(used_quotes);
 
   // Used quotes not reset if it's already true.
   used_quotes = true;
   EscapeString("foo", ninja_options, &used_quotes);
   EXPECT_TRUE(used_quotes);
 }