gn/win: Don't strip trailing = on exec_script arguments.

tools/gn/function_exec_script.cc

Index: tools/gn/function_exec_script.cc
diff --git a/tools/gn/function_exec_script.cc b/tools/gn/function_exec_script.cc
index d5e66ae78cbceecc1fa49a2777df6c1713ac1404..4da361e82aadb25fa6f698e75c9d4cee766d85da 100644
--- a/tools/gn/function_exec_script.cc
+++ b/tools/gn/function_exec_script.cc
@@ -171,8 +171,15 @@ Value RunExecScript(Scope* scope,
   // Make the command line.
   const base::FilePath& python_path = build_settings->python_path();
   base::CommandLine cmdline(python_path);
+
+  // Opt out of CommandLine's parameter processing, which reformats switches
+  // and so on.  For GN, arguments should be passed on exactly like they are
+  // in the .gn file.
+  cmdline.AppendArg("--");

[brettw, 2016/02/22 22:32:45]

I'm confused, won't this pass "--" to Python as well. Or is that OK? If we're
doing that on purpose I'd mention it explicitly, since it's not "exactly whats
in the .gn file".

[Nico, 2016/02/22 22:58:05]

base/command_kind.cc filters out the first -- parameter...it has a somewhat
magic API here.

[brettw, 2016/02/22 23:00:35]

Weird, base::CommandLine is a disaster. Can you mention this in the comment.

+
   cmdline.AppendArgPath(script_path);
 
+

[brettw, 2016/02/22 22:32:45]

Looks like you got an extra line in here.

[Nico, 2016/02/22 22:58:05]

Will remove

   if (args.size() >= 2) {
     // Optional command-line arguments to the script.
     const Value& script_args = args[1];