[PATCH v4 2/5] strbuf_attach: fix all call sites to pass correct alloc
- From
Vaidas Pilkauskas via GitGitGadget <gitgitgadget@gmail.com>
- Date
- Feb 18, 2026, 14:09 UTC
- Message-ID
- <f48b1f07c45f6237f91fa6f746c58b791edef5bd.1771423748.git.gitgitgadget@gmail.com>
- In-Reply-To
- <pull.2008.v4.git.1771423748.gitgitgadget@gmail.com>
From: Vaidas Pilkauskas <vaidas.pilkauskas@shopify.com>
strbuf_attach(sb, buf, len, alloc) requires alloc > len (the buffer must have at least len+1 bytes to hold the NUL). Several call sites passed alloc == len, relying on strbuf_grow(sb, 0) inside strbuf_attach to reallocate. Prepare for changing that by fixing call sites to pass the correct alloc.
- mailinfo, am, refs/files-backend, fast-import, trailer: pass len+1 when the buffer is a NUL-terminated string (or from strbuf_detach). - rerere, apply: ll_merge returns a buffer with exactly result.size bytes (no extra NUL). Use strbuf_add() to copy and NUL-terminate into the strbuf, then free the merge result, so alloc is correct.
Signed-off-by: Vaidas Pilkauskas <vaidas.pilkauskas@shopify.com> --- apply.c | 3 ++- builtin/am.c | 2 +- builtin/fast-import.c | 2 +- mailinfo.c | 2 +- refs/files-backend.c | 2 +- rerere.c | 3 ++- trailer.c | 2 +- 7 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/apply.c b/apply.c index e4c4bf7af9..d67d86bce4 100644 --- a/apply.c +++ b/apply.c @@ -3589,7 +3589,8 @@ static int three_way_merge(struct apply_state *state, return -1; } image_clear(image); - strbuf_attach(&image->buf, result.ptr, result.size, result.size); + strbuf_add(&image->buf, result.ptr, result.size); + free(result.ptr); return status; } diff --git a/builtin/am.c b/builtin/am.c index e0c767e223..c439f868dc 100644 --- a/builtin/am.c +++ b/builtin/am.c @@ -1188,7 +1188,7 @@ static void am_append_signoff(struct am_state *state) { struct strbuf sb = STRBUF_INIT; - strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len); + strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len + 1); append_signoff(&sb, 0, 0); state->msg = strbuf_detach(&sb, &state->msg_len); } diff --git a/builtin/fast-import.c b/builtin/fast-import.c index b8a7757cfd..164d8a6198 100644 --- a/builtin/fast-import.c +++ b/builtin/fast-import.c @@ -3246,7 +3246,7 @@ static void cat_blob(struct object_entry *oe, struct object_id *oid) cat_blob_write("\n", 1); if (oe && oe->pack_id == pack_id) { last_blob.offset = oe->idx.offset; - strbuf_attach(&last_blob.data, buf, size, size); + strbuf_attach(&last_blob.data, buf, size, size + 1); last_blob.depth = oe->depth; } else free(buf); diff --git a/mailinfo.c b/mailinfo.c index a2f06dbd96..13949ff31e 100644 --- a/mailinfo.c +++ b/mailinfo.c @@ -470,7 +470,7 @@ static int convert_to_utf8(struct mailinfo *mi, return error("cannot convert from %s to %s", charset, mi->metainfo_charset); } - strbuf_attach(line, out, out_len, out_len); + strbuf_attach(line, out, out_len, out_len + 1); return 0; } diff --git a/refs/files-backend.c b/refs/files-backend.c index b1b13b41f6..6baba11f96 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -1806,7 +1806,7 @@ static int commit_ref(struct ref_lock *lock) size_t len = strlen(path); struct strbuf sb_path = STRBUF_INIT; - strbuf_attach(&sb_path, path, len, len); + strbuf_attach(&sb_path, path, len, len + 1); /* * If this fails, commit_lock_file() will also fail diff --git a/rerere.c b/rerere.c index 6ec55964e2..2f4809a310 100644 --- a/rerere.c +++ b/rerere.c @@ -1031,7 +1031,8 @@ static int handle_cache(struct index_state *istate, else io.io.output = NULL; strbuf_init(&io.input, 0); - strbuf_attach(&io.input, result.ptr, result.size, result.size); + strbuf_add(&io.input, result.ptr, result.size); + free(result.ptr); /* * Grab the conflict ID and optionally write the original diff --git a/trailer.c b/trailer.c index 911a81ed99..3afe368db0 100644 --- a/trailer.c +++ b/trailer.c @@ -1009,7 +1009,7 @@ static struct trailer_block *trailer_block_get(const struct process_trailer_opti for (ptr = trailer_lines; *ptr; ptr++) { if (last && isspace((*ptr)->buf[0])) { struct strbuf sb = STRBUF_INIT; - strbuf_attach(&sb, *last, strlen(*last), strlen(*last)); + strbuf_attach(&sb, *last, strlen(*last), strlen(*last) + 1); strbuf_addbuf(&sb, *ptr); *last = strbuf_detach(&sb, NULL); continue;
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