Merge branch 'jk/no-looking-at-dotgit-outside-repo'

Update "git diff --no-index" codepath not to try to peek into .git/
directory that happens to be under the current directory, when we
know we are operating outside any repository.

* jk/no-looking-at-dotgit-outside-repo:
  diff: handle sha1 abbreviations outside of repository
  diff_aligned_abbrev: use "struct oid"
  diff_unique_abbrev: rename to diff_aligned_abbrev
  find_unique_abbrev: use 4-buffer ring
  test-*-cache-tree: setup git dir
  read info/{attributes,exclude} only when in repository

1 files changed, 29 insertions, 16 deletions

diff --git a/diff.c b/diff.c
index 5a4e9b31ef..4c09314cc7 100644
--- a/diff.c
+++ b/diff.c
@@ -3096,6 +3096,21 @@ static int similarity_index(struct diff_filepair *p)
 	return p->score * 100 / MAX_SCORE;
 }
 
+static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
+{
+	if (startup_info->have_repository)
+		return find_unique_abbrev(oid->hash, abbrev);
+	else {
+		char *hex = oid_to_hex(oid);
+		if (abbrev < 0)
+			abbrev = FALLBACK_DEFAULT_ABBREV;
+		if (abbrev > GIT_SHA1_HEXSZ)
+			die("BUG: oid abbreviation out of range: %d", abbrev);
+		hex[abbrev] = '\0';
+		return hex;
+	}
+}
+
 static void fill_metainfo(struct strbuf *msg,
 			  const char *name,
 			  const char *other,
@@ -3154,9 +3169,9 @@ static void fill_metainfo(struct strbuf *msg,
 			    (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
 				abbrev = 40;
 		}
-		strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
-			    find_unique_abbrev(one->oid.hash, abbrev));
-		strbuf_add_unique_abbrev(msg, two->oid.hash, abbrev);
+		strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
+			    diff_abbrev_oid(&one->oid, abbrev),
+			    diff_abbrev_oid(&two->oid, abbrev));
 		if (one->mode == two->mode)
 			strbuf_addf(msg, " %06o", one->mode);
 		strbuf_addf(msg, "%s\n", reset);
@@ -4157,18 +4172,15 @@ void diff_free_filepair(struct diff_filepair *p)
 	free(p);
 }
 
-/*
- * This is different from find_unique_abbrev() in that
- * it stuffs the result with dots for alignment.
- */
-const char *diff_unique_abbrev(const unsigned char *sha1, int len)
+const char *diff_aligned_abbrev(const struct object_id *oid, int len)
 {
 	int abblen;
 	const char *abbrev;
-	if (len == 40)
-		return sha1_to_hex(sha1);
 
-	abbrev = find_unique_abbrev(sha1, len);
+	if (len == GIT_SHA1_HEXSZ)
+		return oid_to_hex(oid);
+
+	abbrev = diff_abbrev_oid(oid, len);
 	abblen = strlen(abbrev);
 
 	/*
@@ -4190,15 +4202,16 @@ const char *diff_unique_abbrev(const unsigned char *sha1, int len)
 	 * the automatic sizing is supposed to give abblen that ensures
 	 * uniqueness across all objects (statistically speaking).
 	 */
-	if (abblen < 37) {
-		static char hex[41];
+	if (abblen < GIT_SHA1_HEXSZ - 3) {
+		static char hex[GIT_SHA1_HEXSZ + 1];
 		if (len < abblen && abblen <= len + 2)
 			xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
 		else
 			xsnprintf(hex, sizeof(hex), "%s...", abbrev);
 		return hex;
 	}
-	return sha1_to_hex(sha1);
+
+	return oid_to_hex(oid);
 }
 
 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
@@ -4209,9 +4222,9 @@ static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
 	fprintf(opt->file, "%s", diff_line_prefix(opt));
 	if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
 		fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
-			diff_unique_abbrev(p->one->oid.hash, opt->abbrev));
+			diff_aligned_abbrev(&p->one->oid, opt->abbrev));
 		fprintf(opt->file, "%s ",
-			diff_unique_abbrev(p->two->oid.hash, opt->abbrev));
+			diff_aligned_abbrev(&p->two->oid, opt->abbrev));
 	}
 	if (p->score) {
 		fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),