@matheusbsbs / matheus-bagliano / commits / 4f03666ac6

diff: handle sha1 abbreviations outside of repository

When generating diffs outside a repository (e.g., with "diff --no-index"), we may write abbreviated sha1s as part of "--raw" output or the "index" lines of "--patch" output. Since we have no object database, we never find any collisions, and these sha1s get whatever static abbreviation length is configured (typically 7). However, we do blindly look in ".git/objects" to see if any objects exist, even though we know we are not in a repository. This is usually harmless because such a directory is unlikely to exist, but could be wrong in rare circumstances. Let's instead notice when we are not in a repository and behave as if the object database is empty (i.e., just use the default abbrev length). It would perhaps make sense to be conservative and show full sha1s in that case, but showing the default abbreviation is what we've always done (and is certainly less ugly). Note that this does mean that: cd /not/a/repo GIT_OBJECT_DIRECTORY=/some/real/objdir git diff --no-index ... used to look for collisions in /some/real/objdir but now does not. This could be considered either a bugfix (we do not look at objects if we have no repository) or a regression, but it seems unlikely that anybody would care much either way. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jeff King committed Oct 20, 2016 at 02:21 UTC 4f03666ac69ec4799998f010d04916c12e38edf8

1 file changed +17 -4

diff.c

+17 -4

@@ -3096,6 +3096,19 @@ static int similarity_index(struct diff_filepair *p)

3096 return p->score * 100 / MAX_SCORE;

3097 }

3098

3099 +static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)

3100 +{

3101 + if (startup_info->have_repository)

3102 + return find_unique_abbrev(oid->hash, abbrev);

3103 + else {

3104 + char *hex = oid_to_hex(oid);

3105 + if (abbrev < 0 || abbrev > GIT_SHA1_HEXSZ)

3106 + die("BUG: oid abbreviation out of range: %d", abbrev);

3107 + hex[abbrev] = '\0';

3108 + return hex;

3109 + }

3110 +}

3111 +

3112 static void fill_metainfo(struct strbuf *msg,

3113 const char *name,

3114 const char *other,

@@ -3154,9 +3167,9 @@ static void fill_metainfo(struct strbuf *msg,

3167 (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))

3168 abbrev = 40;

3169 }

3157 - strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,

3158 - find_unique_abbrev(one->oid.hash, abbrev));

3159 - strbuf_add_unique_abbrev(msg, two->oid.hash, abbrev);

3170 + strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,

3171 + diff_abbrev_oid(&one->oid, abbrev),

3172 + diff_abbrev_oid(&two->oid, abbrev));

3173 if (one->mode == two->mode)

3174 strbuf_addf(msg, " %06o", one->mode);

3175 strbuf_addf(msg, "%s\n", reset);

@@ -4165,7 +4178,7 @@ const char *diff_aligned_abbrev(const struct object_id *oid, int len)

4178 if (len == GIT_SHA1_HEXSZ)

4179 return oid_to_hex(oid);

4180

4168 - abbrev = find_unique_abbrev(oid->hash, len);

4181 + abbrev = diff_abbrev_oid(oid, len);

4182 abblen = strlen(abbrev);

4183

4184 /*