fast-import: filemodify after M 040000 <tree> "" crashes

Until M 040000 <tree> "" syntax was introduced in commit 2794ad5
(fast-import: Allow filemodify to set the root, 2010-10-10), it
was impossible for the root entry to refer to an unloaded tree.
Update various functions to take that possibility into account.
Otherwise

	M 040000 <tree> ""
	M 100644 :1 "foo"

and similar commands (using D, C, or R after resetting the root
tree) segfault.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/fast-import.c b/fast-import.c
index 8f68a892342f9fdfb968c4fbc7e17d92cca11765..aaf47c5745f8923fe4787f11cef8abaf6cf8a794 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -1444,7 +1444,7 @@ static int tree_content_set(
        const uint16_t mode,
        struct tree_content *subtree)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        const char *slash1;
        unsigned int i, n;
        struct tree_entry *e;
@@ -1468,6 +1468,9 @@ static int tree_content_set(
        if (!slash1 && !S_ISDIR(mode) && subtree)
                die("Non-directories cannot have subtrees");
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
        for (i = 0; i < t->entry_count; i++) {
                e = t->entries[i];
                if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
@@ -1523,7 +1526,7 @@ static int tree_content_remove(
        const char *p,
        struct tree_entry *backup_leaf)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        const char *slash1;
        unsigned int i, n;
        struct tree_entry *e;
@@ -1534,6 +1537,9 @@ static int tree_content_remove(
        else
                n = strlen(p);
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
        for (i = 0; i < t->entry_count; i++) {
                e = t->entries[i];
                if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
@@ -1581,7 +1587,7 @@ static int tree_content_get(
        const char *p,
        struct tree_entry *leaf)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        const char *slash1;
        unsigned int i, n;
        struct tree_entry *e;
@@ -1592,6 +1598,9 @@ static int tree_content_get(
        else
                n = strlen(p);
 
+       if (!root->tree)
+               load_tree(root);
+       t = root->tree;
        for (i = 0; i < t->entry_count; i++) {
                e = t->entries[i];
                if (e->name->str_len == n && !strncmp(p, e->name->str_dat, n)) {
@@ -2056,13 +2065,16 @@ static uintmax_t do_change_note_fanout(
                char *fullpath, unsigned int fullpath_len,
                unsigned char fanout)
 {
-       struct tree_content *t = root->tree;
+       struct tree_content *t;
        struct tree_entry *e, leaf;
        unsigned int i, tmp_hex_sha1_len, tmp_fullpath_len;
        uintmax_t num_notes = 0;
        unsigned char sha1[20];
        char realpath[60];
 
+       if (!root->tree);
+               load_tree(root);
+       t = root->tree;
        for (i = 0; t && i < t->entry_count; i++) {
                e = t->entries[i];
                tmp_hex_sha1_len = hex_sha1_len + e->name->str_len;

diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 3c0cf0509d2cfe3afc0316ed50ea85cb0d2d14de..1df11adc907aac13b33c3f0e5dbf60467f597e3f 100755 (executable)
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -928,6 +928,43 @@ test_expect_success \
         git diff-tree -C --find-copies-harder -r N5^^ N5 >actual &&
         compare_diff_raw expect actual'
 
+test_expect_success \
+       'N: copy to root by id and modify' \
+       'echo "hello, world" >expect.foo &&
+        echo hello >expect.bar &&
+        git fast-import <<-SETUP_END &&
+       commit refs/heads/N7
+       committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+       data <<COMMIT
+       hello, tree
+       COMMIT
+
+       deleteall
+       M 644 inline foo/bar
+       data <<EOF
+       hello
+       EOF
+       SETUP_END
+
+        tree=$(git rev-parse --verify N7:) &&
+        git fast-import <<-INPUT_END &&
+       commit refs/heads/N8
+       committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+       data <<COMMIT
+       copy to root by id and modify
+       COMMIT
+
+       M 040000 $tree ""
+       M 644 inline foo/foo
+       data <<EOF
+       hello, world
+       EOF
+       INPUT_END
+        git show N8:foo/foo >actual.foo &&
+        git show N8:foo/bar >actual.bar &&
+        test_cmp expect.foo actual.foo &&
+        test_cmp expect.bar actual.bar'
+
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