On 6/6/2018 8:26 AM, Ævar Arnfjörð Bjarmason wrote:
On Wed, Jun 06 2018, Derrick Stolee wrote:
On 6/6/2018 8:11 AM, Ævar Arnfjörð Bjarmason wrote:
On Wed, Jun 06 2018, Derrick Stolee wrote:
Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
---
builtin/commit-graph.c | 39 +++++++++++++--------------------------
commit-graph.c | 15 +++++++--------
commit-graph.h | 7 +++----
3 files changed, 23 insertions(+), 38 deletions(-)
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 3079cde6f9..d8eb8278b3 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -118,13 +118,9 @@ static int graph_read(int argc, const char **argv)
static int graph_write(int argc, const char **argv)
{
- const char **pack_indexes = NULL;
- int packs_nr = 0;
- const char **commit_hex = NULL;
- int commits_nr = 0;
- const char **lines = NULL;
- int lines_nr = 0;
- int lines_alloc = 0;
+ struct string_list *pack_indexes = NULL;
+ struct string_list *commit_hex = NULL;
+ struct string_list lines;
static struct option builtin_commit_graph_write_options[] = {
OPT_STRING(0, "object-dir", &opts.obj_dir,
@@ -150,32 +146,23 @@ static int graph_write(int argc, const char **argv)
if (opts.stdin_packs || opts.stdin_commits) {
struct strbuf buf = STRBUF_INIT;
- lines_nr = 0;
- lines_alloc = 128;
- ALLOC_ARRAY(lines, lines_alloc);
-
- while (strbuf_getline(&buf, stdin) != EOF) {
- ALLOC_GROW(lines, lines_nr + 1, lines_alloc);
- lines[lines_nr++] = strbuf_detach(&buf, NULL);
- }
-
- if (opts.stdin_packs) {
- pack_indexes = lines;
- packs_nr = lines_nr;
- }
- if (opts.stdin_commits) {
- commit_hex = lines;
- commits_nr = lines_nr;
- }
+ string_list_init(&lines, 0);
+
+ while (strbuf_getline(&buf, stdin) != EOF)
+ string_list_append(&lines, strbuf_detach(&buf, NULL));
+
+ if (opts.stdin_packs)
+ pack_indexes = &lines;
+ if (opts.stdin_commits)
+ commit_hex = &lines;
}
write_commit_graph(opts.obj_dir,
pack_indexes,
- packs_nr,
commit_hex,
- commits_nr,
opts.append);
+ string_list_clear(&lines, 0);
return 0;
}
This results in an invalid free() & segfault because you're freeing
&lines which may not have been allocated by string_list_init().
Good point. Did my tests not catch this? (seems it requires calling
`git commit-graph write` with no `--stdin-packs` or
`--stdin-commits`).
Most of your tests (t5318-commit-graph.sh) segfaulted, but presumably
you're on a more forgiving compiler/platform/options. I compiled with
-O0 -g on clang 4.0.1-8 + Debian testing.
I appreciate the extra platform testing. I'm using GCC on Ubuntu (gcc
(Ubuntu 7.3.0-16ubuntu3) 7.3.0).
Monkeypatch on top which I used to fix it:
diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 76423b3fa5..c7eb68aa3a 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -122,6 +122,7 @@ static int graph_write(int argc, const char **argv)
struct string_list *pack_indexes = NULL;
struct string_list *commit_hex = NULL;
struct string_list lines;
+ int free_lines = 0;
static struct option builtin_commit_graph_write_options[] = {
OPT_STRING(0, "object-dir", &opts.obj_dir,
@@ -155,6 +156,7 @@ static int graph_write(int argc, const char **argv)
if (opts.stdin_packs || opts.stdin_commits) {
struct strbuf buf = STRBUF_INIT;
string_list_init(&lines, 0);
+ free_lines = 1;
while (strbuf_getline(&buf, stdin) != EOF)
string_list_append(&lines, strbuf_detach(&buf, NULL));
@@ -170,7 +172,8 @@ static int graph_write(int argc, const char **argv)
commit_hex,
opts.append);
- string_list_clear(&lines, 0);
+ if (free_lines)
+ string_list_clear(&lines, 0);
return 0;
}
But probably having a pointer to the struct which is NULL etc. is
better.
Wouldn't the easiest fix be to call `string_list_init(&lines, 0)`
outside of any conditional?
Sure that works too. We'd be doing the init when we don't need it, but
it's not like this part is performance critical or anything...
