#include "builtin.h"
 #include "grep.h"
 
+#ifndef NO_EXTERNAL_GREP
+#ifdef __unix__
+#define NO_EXTERNAL_GREP 0
+#else
+#define NO_EXTERNAL_GREP 1
+#endif
+#endif
+
 /*
  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  * pathname wildcards are allowed.
        return i;
 }
 
-#ifdef __unix__
+#if !NO_EXTERNAL_GREP
 static int exec_grep(int argc, const char **argv)
 {
        pid_t pid;
                        if (opt->pre_context) {
                                push_arg("-B");
                                len += snprintf(argptr, sizeof(randarg)-len,
-                                               "%u", opt->pre_context);
+                                               "%u", opt->pre_context) + 1;
                                if (sizeof(randarg) <= len)
                                        die("maximum length of args exceeded");
                                push_arg(argptr);
                        if (opt->post_context) {
                                push_arg("-A");
                                len += snprintf(argptr, sizeof(randarg)-len,
-                                               "%u", opt->post_context);
+                                               "%u", opt->post_context) + 1;
                                if (sizeof(randarg) <= len)
                                        die("maximum length of args exceeded");
                                push_arg(argptr);
                else {
                        push_arg("-C");
                        len += snprintf(argptr, sizeof(randarg)-len,
-                                       "%u", opt->post_context);
+                                       "%u", opt->post_context) + 1;
                        if (sizeof(randarg) <= len)
                                die("maximum length of args exceeded");
                        push_arg(argptr);
                struct cache_entry *ce = active_cache[i];
                char *name;
                int kept;
-               if (!S_ISREG(ntohl(ce->ce_mode)))
+               if (!S_ISREG(ce->ce_mode))
                        continue;
                if (!pathspec_matches(paths, ce->name))
                        continue;
                        memcpy(name + 2, ce->name, len + 1);
                }
                argv[argc++] = name;
-               if (argc < MAXARGS)
-                       continue;
-               status = flush_grep(opt, argc, nr, argv, &kept);
-               if (0 < status)
-                       hit = 1;
-               argc = nr + kept;
+               if (MAXARGS <= argc) {
+                       status = flush_grep(opt, argc, nr, argv, &kept);
+                       if (0 < status)
+                               hit = 1;
+                       argc = nr + kept;
+               }
                if (ce_stage(ce)) {
                        do {
                                i++;
        int nr;
        read_cache();
 
-#ifdef __unix__
+#if !NO_EXTERNAL_GREP
        /*
         * Use the external "grep" command for the case where
         * we grep through the checked-out files. It tends to
 
        for (nr = 0; nr < active_nr; nr++) {
                struct cache_entry *ce = active_cache[nr];
-               if (!S_ISREG(ntohl(ce->ce_mode)))
+               if (!S_ISREG(ce->ce_mode))
                        continue;
                if (!pathspec_matches(paths, ce->name))
                        continue;
                        continue;
                }
                if (!strcmp("-l", arg) ||
+                   !strcmp("--name-only", arg) ||
                    !strcmp("--files-with-matches", arg)) {
                        opt.name_only = 1;
                        continue;
                                die("'%s': %s", argv[1], strerror(errno));
                        while (fgets(buf, sizeof(buf), patterns)) {
                                int len = strlen(buf);
-                               if (buf[len-1] == '\n')
+                               if (len && buf[len-1] == '\n')
                                        buf[len-1] = 0;
                                /* ignore empty line like grep does */
                                if (!buf[0])