Merge branch 'js/difftool-builtin'
authorJunio C Hamano <gitster@pobox.com>
Mon, 17 Apr 2017 06:29:34 +0000 (23:29 -0700)
committerJunio C Hamano <gitster@pobox.com>
Mon, 17 Apr 2017 06:29:34 +0000 (23:29 -0700)
Code cleanup.

* js/difftool-builtin:
  difftool: fix use-after-free
  difftool: avoid strcpy

builtin/difftool.c
t/t7800-difftool.sh

index 25e54ad..1354d0e 100644 (file)
@@ -297,6 +297,19 @@ static char *get_symlink(const struct object_id *oid, const char *path)
        return data;
 }
 
+static int checkout_path(unsigned mode, struct object_id *oid,
+                        const char *path, const struct checkout *state)
+{
+       struct cache_entry *ce;
+       int ret;
+
+       ce = make_cache_entry(mode, oid->hash, path, 0, 0);
+       ret = checkout_entry(ce, state, NULL);
+
+       free(ce);
+       return ret;
+}
+
 static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                        int argc, const char **argv)
 {
@@ -305,8 +318,8 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        struct strbuf rpath = STRBUF_INIT, buf = STRBUF_INIT;
        struct strbuf ldir = STRBUF_INIT, rdir = STRBUF_INIT;
        struct strbuf wtdir = STRBUF_INIT;
+       char *lbase_dir, *rbase_dir;
        size_t ldir_len, rdir_len, wtdir_len;
-       struct cache_entry *ce = xcalloc(1, sizeof(ce) + PATH_MAX + 1);
        const char *workdir, *tmp;
        int ret = 0, i;
        FILE *fp;
@@ -339,11 +352,11 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
        memset(&wtindex, 0, sizeof(wtindex));
 
        memset(&lstate, 0, sizeof(lstate));
-       lstate.base_dir = ldir.buf;
+       lstate.base_dir = lbase_dir = xstrdup(ldir.buf);
        lstate.base_dir_len = ldir.len;
        lstate.force = 1;
        memset(&rstate, 0, sizeof(rstate));
-       rstate.base_dir = rdir.buf;
+       rstate.base_dir = rbase_dir = xstrdup(rdir.buf);
        rstate.base_dir_len = rdir.len;
        rstate.force = 1;
 
@@ -377,7 +390,6 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                struct object_id loid, roid;
                char status;
                const char *src_path, *dst_path;
-               size_t src_path_len, dst_path_len;
 
                if (starts_with(info.buf, "::"))
                        die(N_("combined diff formats('-c' and '--cc') are "
@@ -390,17 +402,14 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                if (strbuf_getline_nul(&lpath, fp))
                        break;
                src_path = lpath.buf;
-               src_path_len = lpath.len;
 
                i++;
                if (status != 'C' && status != 'R') {
                        dst_path = src_path;
-                       dst_path_len = src_path_len;
                } else {
                        if (strbuf_getline_nul(&rpath, fp))
                                break;
                        dst_path = rpath.buf;
-                       dst_path_len = rpath.len;
                }
 
                if (S_ISGITLINK(lmode) || S_ISGITLINK(rmode)) {
@@ -430,11 +439,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                }
 
                if (lmode && status != 'C') {
-                       ce->ce_mode = lmode;
-                       oidcpy(&ce->oid, &loid);
-                       strcpy(ce->name, src_path);
-                       ce->ce_namelen = src_path_len;
-                       if (checkout_entry(ce, &lstate, NULL))
+                       if (checkout_path(lmode, &loid, src_path, &lstate))
                                return error("could not write '%s'", src_path);
                }
 
@@ -451,11 +456,7 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                        hashmap_add(&working_tree_dups, entry);
 
                        if (!use_wt_file(workdir, dst_path, &roid)) {
-                               ce->ce_mode = rmode;
-                               oidcpy(&ce->oid, &roid);
-                               strcpy(ce->name, dst_path);
-                               ce->ce_namelen = dst_path_len;
-                               if (checkout_entry(ce, &rstate, NULL))
+                               if (checkout_path(rmode, &roid, dst_path, &rstate))
                                        return error("could not write '%s'",
                                                     dst_path);
                        } else if (!is_null_oid(&roid)) {
@@ -625,7 +626,8 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
                exit_cleanup(tmpdir, rc);
 
 finish:
-       free(ce);
+       free(lbase_dir);
+       free(rbase_dir);
        strbuf_release(&ldir);
        strbuf_release(&rdir);
        strbuf_release(&wtdir);
index 0e7f30d..7f09867 100755 (executable)
@@ -393,6 +393,25 @@ test_expect_success 'setup change in subdirectory' '
        git commit -m "modified both"
 '
 
+test_expect_success 'difftool -d with growing paths' '
+       a=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa &&
+       git init growing &&
+       (
+               cd growing &&
+               echo "test -f \"\$2/b\"" | write_script .git/test-for-b.sh &&
+               one=$(printf 1 | git hash-object -w --stdin) &&
+               two=$(printf 2 | git hash-object -w --stdin) &&
+               git update-index --add \
+                       --cacheinfo 100644,$one,$a --cacheinfo 100644,$two,b &&
+               tree1=$(git write-tree) &&
+               git update-index --add \
+                       --cacheinfo 100644,$two,$a --cacheinfo 100644,$one,b &&
+               tree2=$(git write-tree) &&
+               git checkout -- $a &&
+               git difftool -d --extcmd .git/test-for-b.sh $tree1 $tree2
+       )
+'
+
 run_dir_diff_test () {
        test_expect_success "$1 --no-symlinks" "
                symlinks=--no-symlinks &&