Merge 'fix-is-exe' into HEAD

Author: dscho

help.c

@@ -105,16 +105,31 @@ static int is_executable(const char *name)
 		return 0;
 
 #if defined(GIT_WINDOWS_NATIVE)
-{	/* cannot trust the executable bit, peek into the file instead */
+	/*
+	 * On Windows there is no executable bit. The file extension
+	 * indicates whether it can be run as an executable, and Git
+	 * has special-handling to detect scripts and launch them
+	 * through the indicated script interpreter. We test for the
+	 * file extension first because virus scanners may make
+	 * opening an executable for reading expensive.
+	 */
+	if (ends_with(name, ".exe"))
+		return S_IXUSR;
+
+{
+	/*
+	 * Now that we know it does not have an executable extension,
+	 * peek into the file instead.
+	 */
 	char buf[3] = { 0 };
 	int n;
 	int fd = open(name, O_RDONLY);
 	st.st_mode &= ~S_IXUSR;
 	if (fd >= 0) {
 		n = read(fd, buf, 2);
 		if (n == 2)
-			/* DOS executables start with "MZ" */
-			if (!strcmp(buf, "#!") || !strcmp(buf, "MZ"))
+			/* look for a she-bang */
+			if (!strcmp(buf, "#!"))
 				st.st_mode |= S_IXUSR;
 		close(fd);
 	}