diff: include oid length in deltas

Now that `git_diff_delta` data can be produced by reading patch
file data, which may have an abbreviated oid, allow consumers to
know that the id is abbreviated.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/diff_print.c b/src/diff_print.c
index 09bf77aef..7c9af2449 100644
--- a/src/diff_print.c
+++ b/src/diff_print.c
@@ -208,6 +208,7 @@ static int diff_print_one_raw(
 {
 	diff_print_info *pi = data;
 	git_buf *out = pi->buf;
+	int id_abbrev;
 	char code = git_diff_status_char(delta->status);
 	char start_oid[GIT_OID_HEXSZ+1], end_oid[GIT_OID_HEXSZ+1];
 
@@ -218,6 +219,16 @@ static int diff_print_one_raw(
 
 	git_buf_clear(out);
 
+	id_abbrev = delta->old_file.mode ? delta->old_file.id_abbrev :
+		delta->new_file.id_abbrev;
+
+	if (pi->oid_strlen - 1 > id_abbrev) {
+		giterr_set(GITERR_PATCH,
+			"The patch input contains %d id characters (cannot print %d)",
+			id_abbrev, pi->oid_strlen);
+		return -1;
+	}
+
 	git_oid_tostr(start_oid, pi->oid_strlen, &delta->old_file.id);
 	git_oid_tostr(end_oid, pi->oid_strlen, &delta->new_file.id);
 
@@ -252,6 +263,22 @@ static int diff_print_oid_range(
 {
 	char start_oid[GIT_OID_HEXSZ+1], end_oid[GIT_OID_HEXSZ+1];
 
+	if (delta->old_file.mode &&
+			oid_strlen - 1 > delta->old_file.id_abbrev) {
+		giterr_set(GITERR_PATCH,
+			"The patch input contains %d id characters (cannot print %d)",
+			delta->old_file.id_abbrev, oid_strlen);
+		return -1;
+	}
+
+	if ((delta->new_file.mode &&
+			oid_strlen - 1 > delta->new_file.id_abbrev)) {
+		giterr_set(GITERR_PATCH,
+			"The patch input contains %d id characters (cannot print %d)",
+			delta->new_file.id_abbrev, oid_strlen);
+		return -1;
+	}
+
 	git_oid_tostr(start_oid, oid_strlen, &delta->old_file.id);
 	git_oid_tostr(end_oid, oid_strlen, &delta->new_file.id);