From 5edde510181357b0d0376d5542ddfa51a7e7ba12 Mon Sep 17 00:00:00 2001
From: Jonathan Nieder <jrnieder@gmail.com>
Date: Sun, 17 Oct 2010 20:03:38 -0500
Subject: 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>
---
 fast-import.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

(limited to 'fast-import.c')

diff --git a/fast-import.c b/fast-import.c
index 8f68a89234..aaf47c5745 100644
--- 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;
-- 
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