[PATCH 1/3] pack-write: use more idiomatic strbuf usage for packname construction

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change code added in 5889271114a (finish_tmp_packfile():use strbuf for
pathname construction, 2014-03-03) to do strbuf_reset() instead of
noting the length of the base template, and doing a strbuf_setlen() to
reset it, also change the spacing in the finish_tmp_packfile() so that
each setup of the template, rename, and strbuf_reset() is grouped
together.

Since the prototype of the previous "name_buffer" now has a "const"
use this chance to wrap the overly long definition of the
finish_tmp_packfile() function.

This doesn't really matter for now, but as we'll see makes the
subsequent change much easier, as we won't need to juggle the basename
template v.s. its current contents anymore when writing bitmaps.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 builtin/pack-objects.c | 17 +++++++++++------
 pack-write.c           | 27 ++++++++++++---------------
 pack.h                 |  7 ++++++-
 3 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index df49f656b96..717003563db 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1216,7 +1216,7 @@ static void write_pack_file(void)
 
 		if (!pack_to_stdout) {
 			struct stat st;
-			struct strbuf tmpname = STRBUF_INIT;
+			struct strbuf tmp_basename = STRBUF_INIT;
 
 			/*
 			 * Packs are runtime accessed in their mtime
@@ -1237,7 +1237,7 @@ static void write_pack_file(void)
 					warning_errno(_("failed utime() on %s"), pack_tmp_name);
 			}
 
-			strbuf_addf(&tmpname, "%s-", base_name);
+			strbuf_addf(&tmp_basename, "%s-", base_name);
 
 			if (write_bitmap_index) {
 				bitmap_writer_set_checksum(hash);
@@ -1245,12 +1245,16 @@ static void write_pack_file(void)
 					&to_pack, written_list, nr_written);
 			}
 
-			finish_tmp_packfile(&tmpname, pack_tmp_name,
+			finish_tmp_packfile(&tmp_basename, pack_tmp_name,
 					    written_list, nr_written,
 					    &pack_idx_opts, hash);
 
 			if (write_bitmap_index) {
-				strbuf_addf(&tmpname, "%s.bitmap", hash_to_hex(hash));
+				struct strbuf sb = STRBUF_INIT;
+
+				strbuf_addf(&sb, "%s%s.bitmap",
+					    tmp_basename.buf,
+					    hash_to_hex(hash));
 
 				stop_progress(&progress_state);
 
@@ -1258,11 +1262,12 @@ static void write_pack_file(void)
 				bitmap_writer_select_commits(indexed_commits, indexed_commits_nr, -1);
 				bitmap_writer_build(&to_pack);
 				bitmap_writer_finish(written_list, nr_written,
-						     tmpname.buf, write_bitmap_options);
+						     sb.buf, write_bitmap_options);
 				write_bitmap_index = 0;
+				strbuf_release(&sb);
 			}
 
-			strbuf_release(&tmpname);
+			strbuf_release(&tmp_basename);
 			free(pack_tmp_name);
 			puts(hash_to_hex(hash));
 		}
diff --git a/pack-write.c b/pack-write.c
index 277c60165e8..57b9fc11423 100644
--- a/pack-write.c
+++ b/pack-write.c
@@ -462,15 +462,15 @@ struct hashfile *create_tmp_packfile(char **pack_tmp_name)
 	return hashfd(fd, *pack_tmp_name);
 }
 
-void finish_tmp_packfile(struct strbuf *name_buffer,
+void finish_tmp_packfile(const struct strbuf *tmp_basename,
 			 const char *pack_tmp_name,
 			 struct pack_idx_entry **written_list,
 			 uint32_t nr_written,
 			 struct pack_idx_option *pack_idx_opts,
 			 unsigned char hash[])
 {
+	struct strbuf sb = STRBUF_INIT;
 	const char *idx_tmp_name, *rev_tmp_name = NULL;
-	int basename_len = name_buffer->len;
 
 	if (adjust_shared_perm(pack_tmp_name))
 		die_errno("unable to make temporary pack file readable");
@@ -483,26 +483,23 @@ void finish_tmp_packfile(struct strbuf *name_buffer,
 	rev_tmp_name = write_rev_file(NULL, written_list, nr_written, hash,
 				      pack_idx_opts->flags);
 
-	strbuf_addf(name_buffer, "%s.pack", hash_to_hex(hash));
-
-	if (rename(pack_tmp_name, name_buffer->buf))
+	strbuf_addf(&sb, "%s%s.pack", tmp_basename->buf, hash_to_hex(hash));
+	if (rename(pack_tmp_name, sb.buf))
 		die_errno("unable to rename temporary pack file");
-
-	strbuf_setlen(name_buffer, basename_len);
+	strbuf_reset(&sb);
 
 	if (rev_tmp_name) {
-		strbuf_addf(name_buffer, "%s.rev", hash_to_hex(hash));
-		if (rename(rev_tmp_name, name_buffer->buf))
+		strbuf_addf(&sb, "%s%s.rev", tmp_basename->buf,
+			    hash_to_hex(hash));
+		if (rename(rev_tmp_name, sb.buf))
 			die_errno("unable to rename temporary reverse-index file");
-
-		strbuf_setlen(name_buffer, basename_len);
+		strbuf_reset(&sb);
 	}
 
-	strbuf_addf(name_buffer, "%s.idx", hash_to_hex(hash));
-	if (rename(idx_tmp_name, name_buffer->buf))
+	strbuf_addf(&sb, "%s%s.idx", tmp_basename->buf, hash_to_hex(hash));
+	if (rename(idx_tmp_name, sb.buf))
 		die_errno("unable to rename temporary index file");
-
-	strbuf_setlen(name_buffer, basename_len);
+	strbuf_reset(&sb);
 
 	free((void *)idx_tmp_name);
 }
diff --git a/pack.h b/pack.h
index fa139545262..ae0c9e04cd9 100644
--- a/pack.h
+++ b/pack.h
@@ -110,6 +110,11 @@ int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
 int read_pack_header(int fd, struct pack_header *);
 
 struct hashfile *create_tmp_packfile(char **pack_tmp_name);
-void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
+void finish_tmp_packfile(const struct strbuf *name_buffer,
+			 const char *pack_tmp_name,
+			 struct pack_idx_entry **written_list,
+			 uint32_t nr_written,
+			 struct pack_idx_option *pack_idx_opts,
+			 unsigned char sha1[]);
 
 #endif
-- 
2.33.0.818.gd2ef2916285