completion: extract repository discovery from __gitdir()

diff --git a/help.c b/help.c
index 53e2a67e0052b7abb9f01e075f76c4eb5f35cbfc..bc6cd19cf3a5e4300e32cbdd437b2d9231fd2d89 100644 (file)
--- a/help.c
+++ b/help.c
@@ -105,7 +105,22 @@ 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
+        * it quite expensive to open many files.
+        */
+       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);
@@ -113,8 +128,8 @@ static int is_executable(const char *name)
        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);
        }