Win32: Unicode arguments (outgoing)

Convert command line arguments from UTF-8 to UTF-16 when creating other
processes.

Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

compat/mingw.c

@@ -831,9 +831,10 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 			      const char *dir,
 			      int prepend_cmd, int fhin, int fhout, int fherr)
 {
-	STARTUPINFO si;
+	STARTUPINFOW si;
 	PROCESS_INFORMATION pi;
 	struct strbuf envblk, args;
+	wchar_t wcmd[MAX_PATH], wdir[MAX_PATH], *wargs;
 	unsigned flags;
 	BOOL ret;
 
@@ -869,6 +870,11 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 	si.hStdOutput = winansi_get_osfhandle(fhout);
 	si.hStdError = winansi_get_osfhandle(fherr);
 
+	if (xutftowcs_path(wcmd, cmd) < 0)
+		return -1;
+	if (dir && xutftowcs_path(wdir, dir) < 0)
+		return -1;
+
 	/* concatenate argv, quoting args as we go */
 	strbuf_init(&args, 0);
 	if (prepend_cmd) {
@@ -886,6 +892,10 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 			free(quoted);
 	}
 
+	wargs = xmalloc((2 * args.len + 1) * sizeof(wchar_t));
+	xutftowcs(wargs, args.buf, 2 * args.len + 1);
+	strbuf_release(&args);
+
 	if (env) {
 		int count = 0;
 		char **e, **sorted_env;
@@ -907,12 +917,12 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 	}
 
 	memset(&pi, 0, sizeof(pi));
-	ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
-		env ? envblk.buf : NULL, dir, &si, &pi);
+	ret = CreateProcessW(wcmd, wargs, NULL, NULL, TRUE, flags,
+		env ? envblk.buf : NULL, dir ? wdir : NULL, &si, &pi);
 
 	if (env)
 		strbuf_release(&envblk);
-	strbuf_release(&args);
+	free(wargs);
 
 	if (!ret) {
 		errno = ENOENT;