commit 5a7e39c0cbca3f2b94834167154472a61fc34a03
Author: Sebastian Hahn <sebastian(a)torproject.org>
Date: Mon Apr 17 10:07:31 2017 +0200
Fix diff generation with line added at start
The consdiff generation logic would skip over lines added at the start of the
second file, and generate a diff that it would the immediately refuse because
it couldn't be used to reproduce the second file from the first. Fixes #21996.
---
src/or/consdiff.c | 2 +-
src/test/test_consdiff.c | 11 +++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/src/or/consdiff.c b/src/or/consdiff.c
index d2a2af1..cd22fd4 100644
--- a/src/or/consdiff.c
+++ b/src/or/consdiff.c
@@ -671,7 +671,7 @@ gen_ed_diff(const smartlist_t *cons1, const smartlist_t *cons2,
*/
i1=len1-1, i2=len2-1;
char buf[128];
- while (i1 > 0 || i2 > 0) {
+ while (i1 >= 0 || i2 >= 0) {
int start1x, start2x, end1, end2, added, deleted;
diff --git a/src/test/test_consdiff.c b/src/test/test_consdiff.c
index 1b4e2ad..193d524 100644
--- a/src/test/test_consdiff.c
+++ b/src/test/test_consdiff.c
@@ -622,6 +622,17 @@ test_consdiff_gen_ed_diff(void *arg)
tt_str_eq_line(".", smartlist_get(diff, 5));
tt_str_eq_line("2d", smartlist_get(diff, 6));
+ smartlist_clear(cons1);
+ smartlist_clear(cons2);
+ consensus_split_lines(cons1, "B\n", area);
+ consensus_split_lines(cons2, "A\nB\n", area);
+ diff = gen_ed_diff(cons1, cons2, area);
+ tt_ptr_op(NULL, OP_NE, diff);
+ tt_int_op(3, OP_EQ, smartlist_len(diff));
+ tt_str_eq_line("0a", smartlist_get(diff, 0));
+ tt_str_eq_line("A", smartlist_get(diff, 1));
+ tt_str_eq_line(".", smartlist_get(diff, 2));
+
/* TODO: small real use-cases, i.e. consensuses. */
done: