[PATCH v3 00/11] rerere: handle nested conflicts
- From
Thomas Gummerer <t.gummerer@gmail.com>
- Date
- Jul 14, 2018, 21:44 UTC
- Message-ID
- <20180714214443.7184-1-t.gummerer@gmail.com>
- In-Reply-To
- <20180605215219.28783-1-t.gummerer@gmail.com>
The previous rounds were at <20180520211210.1248-1-t.gummerer@gmail.com> and <20180605215219.28783-1-t.gummerer@gmail.com>.
This round is a more polished version of the previous round, as suggested by Junio in <xmqq1scgmemy.fsf@gitster-ct.c.googlers.com>. It's also rebased on v2.18.
The series grew by one patch, because 8/10 has been split into two patches hopefully making it easier to follow.
range-diff before below:
1: 2825342cc2 = 1: 018bd68a8a rerere: unify error messages when read_cache fails
2: d1500028aa ! 2: 281fcbf24f rerere: lowercase error messages
@@ -4,7 +4,8 @@
Documentation/CodingGuidelines mentions that error messages should be
lowercase. Prior to marking them for translation follow that pattern
- in rerere as well.
+ in rerere as well, so translators won't have to translate messages
+ that don't conform to our guidelines.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
@@ -87,3 +88,12 @@
/* Nuke the recorded resolution for the conflict */
id = new_rerere_id(sha1);
+@@
+ handle_cache(path, sha1, rerere_path(id, "thisimage"));
+ if (read_mmfile(&cur, rerere_path(id, "thisimage"))) {
+ free(cur.ptr);
+- error("Failed to update conflicted state in '%s'", path);
++ error("failed to update conflicted state in '%s'", path);
+ goto fail_exit;
+ }
+ cleanly_resolved = !try_merge(id, path, &cur, &result);
3: ed3601ee71 = 3: b6d5e2e26d rerere: wrap paths in output in sq
4: 6ead84a199 ! 4: 45f0d7a99f rerere: mark strings for translation
@@ -4,7 +4,7 @@
'git rerere' is considered a plumbing command and as such its output
should be translated. Its functionality is also only enabled through
- a config setting, so scripts really shouldn't rely on its output
+ a config setting, so scripts really shouldn't rely on the output
either way.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
@@ -219,8 +219,8 @@
handle_cache(path, sha1, rerere_path(id, "thisimage"));
if (read_mmfile(&cur, rerere_path(id, "thisimage"))) {
free(cur.ptr);
-- error("Failed to update conflicted state in '%s'", path);
-+ error(_("Failed to update conflicted state in '%s'"), path);
+- error("failed to update conflicted state in '%s'", path);
++ error(_("failed to update conflicted state in '%s'"), path);
goto fail_exit;
}
cleanly_resolved = !try_merge(id, path, &cur, &result);
5: caad276aca ! 5: 993857a816 rerere: add some documentation
@@ -1,6 +1,6 @@
Author: Thomas Gummerer <t.gummerer@gmail.com>
- rerere: add some documentation
+ rerere: add documentation for conflict normalization
Add some documentation for the logic behind the conflict normalization
in rerere.
@@ -27,30 +27,28 @@
+when different conflict style settings are used, rerere normalizes the
+conflicts before writing them to the rerere database.
+
-+Differnt conflict styles and branch names are dealt with by stripping
-+that information from the conflict markers, and removing extraneous
-+information from the `diff3` conflict style.
-+
-+Branches being merged in different order are dealt with by sorting the
-+conflict hunks. More on each of those parts in the following
-+sections.
++Different conflict styles and branch names are normalized by stripping
++the labels from the conflict markers, and removing extraneous
++information from the `diff3` conflict style. Branches that are merged
++in different order are normalized by sorting the conflict hunks. More
++on each of those steps in the following sections.
+
+Once these two normalization operations are applied, a conflict ID is
-+created based on the normalized conflict, which is later used by
++calculated based on the normalized conflict, which is later used by
+rerere to look up the conflict in the rerere database.
+
+Stripping extraneous information
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Say we have three branches AB, AC and AC2. The common ancestor of
-+these branches has a file with with a line with the string "A" (for
-+brevity this line is called "line A" for brevity in the following) in
-+it. In branch AB this line is changed to "B", in AC, this line is
-+changed to C, and branch AC2 is forked off of AC, after the line was
-+changed to C.
++these branches has a file with a line containing the string "A" (for
++brevity this is called "line A" in the rest of the document). In
++branch AB this line is changed to "B", in AC, this line is changed to
++"C", and branch AC2 is forked off of AC, after the line was changed to
++"C".
+
-+Now forking a branch ABAC off of branch AB and then merging AC into it,
-+we'd get a conflict like the following:
++Forking a branch ABAC off of branch AB and then merging AC into it, we
++get a conflict like the following:
+
+ <<<<<<< HEAD
+ B
@@ -58,9 +56,9 @@
+ C
+ >>>>>>> AC
+
-+Now doing the analogous with AC2 (forking a branch ABAC2 off of branch
-+AB and then merging branch AC2 into it), maybe using the diff3
-+conflict style, we'd get a conflict like the following:
++Doing the analogous with AC2 (forking a branch ABAC2 off of branch AB
++and then merging branch AC2 into it), using the diff3 conflict style,
++we get a conflict like the following:
+
+ <<<<<<< HEAD
+ B
6: ad88a6b8a8 = 6: a7a0f657f3 rerere: fix crash when conflict goes unresolved
7: 15f9efcba6 = 7: f1afd4b9a4 rerere: only return whether a path has conflicts or not
8: 1490efaad3 ! 8: 1f5cef506a rerere: factor out handle_conflict function
@@ -3,53 +3,14 @@
rerere: factor out handle_conflict function
Factor out the handle_conflict function, which handles a single
- conflict in a path. This is a preparation for the next step, where
- this function will be re-used. No functional changes intended.
+ conflict in a path. This is in preparation for a subsequent commit,
+ where this function will be re-used. No functional changes intended.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
diff --git a/rerere.c b/rerere.c
--- a/rerere.c
+++ b/rerere.c
-@@
- ferr_puts(str, io->output, &io->wrerror);
- }
-
--/*
-- * Write a conflict marker to io->output (if defined).
-- */
--static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
--{
-- char buf[64];
--
-- while (size) {
-- if (size <= sizeof(buf) - 2) {
-- memset(buf, ch, size);
-- buf[size] = '\n';
-- buf[size + 1] = '\0';
-- size = 0;
-- } else {
-- int sz = sizeof(buf) - 1;
--
-- /*
-- * Make sure we will not write everything out
-- * in this round by leaving at least 1 byte
-- * for the next round, giving the next round
-- * a chance to add the terminating LF. Yuck.
-- */
-- if (size <= sz)
-- sz -= (sz - size) + 1;
-- memset(buf, ch, sz);
-- buf[sz] = '\0';
-- size -= sz;
-- }
-- rerere_io_putstr(buf, io);
-- }
--}
--
- static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
- {
- if (io->output)
@@
return isspace(*buf);
}
@@ -67,14 +28,7 @@
- * hunks and -1 if an error occured.
- */
-static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
-+static void rerere_strbuf_putconflict(struct strbuf *buf, int ch, size_t size)
-+{
-+ strbuf_addchars(buf, ch, size);
-+ strbuf_addch(buf, '\n');
-+}
-+
-+static int handle_conflict(struct strbuf *out, struct rerere_io *io,
-+ int marker_size, git_SHA_CTX *ctx)
++static int handle_conflict(struct rerere_io *io, int marker_size, git_SHA_CTX *ctx)
{
- git_SHA_CTX ctx;
- int has_conflicts = 0;
@@ -88,38 +42,39 @@
-
- if (sha1)
- git_SHA1_Init(&ctx);
--
-+ int has_conflicts = 1;
++ int has_conflicts = -1;
+
while (!io->getline(&buf, io)) {
-- if (is_cmarker(buf.buf, '<', marker_size)) {
+ if (is_cmarker(buf.buf, '<', marker_size)) {
- if (hunk != RR_CONTEXT)
- goto bad;
- hunk = RR_SIDE_1;
-- } else if (is_cmarker(buf.buf, '|', marker_size)) {
-+ if (is_cmarker(buf.buf, '<', marker_size))
-+ goto bad;
-+ else if (is_cmarker(buf.buf, '|', marker_size)) {
++ break;
+ } else if (is_cmarker(buf.buf, '|', marker_size)) {
if (hunk != RR_SIDE_1)
- goto bad;
+- goto bad;
++ break;
hunk = RR_ORIGINAL;
-@@
- goto bad;
+ } else if (is_cmarker(buf.buf, '=', marker_size)) {
+ if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
+- goto bad;
++ break;
+ hunk = RR_SIDE_2;
+ } else if (is_cmarker(buf.buf, '>', marker_size)) {
+ if (hunk != RR_SIDE_2)
+- goto bad;
++ break;
if (strbuf_cmp(&one, &two) > 0)
strbuf_swap(&one, &two);
-- has_conflicts = 1;
+ has_conflicts = 1;
- hunk = RR_CONTEXT;
-- rerere_io_putconflict('<', marker_size, io);
-- rerere_io_putmem(one.buf, one.len, io);
-- rerere_io_putconflict('=', marker_size, io);
-- rerere_io_putmem(two.buf, two.len, io);
-- rerere_io_putconflict('>', marker_size, io);
+ rerere_io_putconflict('<', marker_size, io);
+ rerere_io_putmem(one.buf, one.len, io);
+ rerere_io_putconflict('=', marker_size, io);
+ rerere_io_putmem(two.buf, two.len, io);
+ rerere_io_putconflict('>', marker_size, io);
- if (sha1) {
- git_SHA1_Update(&ctx, one.buf ? one.buf : "",
-+ rerere_strbuf_putconflict(out, '<', marker_size);
-+ strbuf_addbuf(out, &one);
-+ rerere_strbuf_putconflict(out, '=', marker_size);
-+ strbuf_addbuf(out, &two);
-+ rerere_strbuf_putconflict(out, '>', marker_size);
+ if (ctx) {
+ git_SHA1_Update(ctx, one.buf ? one.buf : "",
one.len + 1);
@@ -129,7 +84,7 @@
}
- strbuf_reset(&one);
- strbuf_reset(&two);
-+ goto out;
++ break;
} else if (hunk == RR_SIDE_1)
strbuf_addbuf(&one, &buf);
else if (hunk == RR_ORIGINAL)
@@ -143,9 +98,6 @@
- hunk = 99; /* force error exit */
- break;
}
-+bad:
-+ has_conflicts = -1;
-+out:
strbuf_release(&one);
strbuf_release(&two);
strbuf_release(&buf);
@@ -169,24 +121,20 @@
+{
+ git_SHA_CTX ctx;
+ struct strbuf buf = STRBUF_INIT;
-+ struct strbuf out = STRBUF_INIT;
+ int has_conflicts = 0;
+ if (sha1)
+ git_SHA1_Init(&ctx);
+
+ while (!io->getline(&buf, io)) {
+ if (is_cmarker(buf.buf, '<', marker_size)) {
-+ has_conflicts = handle_conflict(&out, io, marker_size,
-+ sha1 ? &ctx : NULL);
++ has_conflicts = handle_conflict(io, marker_size,
++ sha1 ? &ctx : NULL);
+ if (has_conflicts < 0)
+ break;
-+ rerere_io_putmem(out.buf, out.len, io);
-+ strbuf_reset(&out);
+ } else
+ rerere_io_putstr(buf.buf, io);
+ }
+ strbuf_release(&buf);
-+ strbuf_release(&out);
+
if (sha1)
git_SHA1_Final(sha1, &ctx);
-: ---------- > 9: 8ac0d3e903 rerere: return strbuf from handle path
9: 6619650c42 ! 10: ef84fdc201 rerere: teach rerere to handle nested conflicts
@@ -27,7 +27,7 @@
>>>>>>> branch-2
>>>>>>> branch-3~
- it would be reordered as follows in the preimage:
+ it would be recorde as follows in the preimage:
<<<<<<<
1
@@ -40,14 +40,16 @@
>>>>>>>
and the conflict ID would be calculated as
+
sha1(1<NUL><<<<<<<
2
=======
3
>>>>>>><NUL>)
- Stripping out vs. leaving the conflict markers in place should have no
- practical impact, but it simplifies the implementation.
+ Stripping out vs. leaving the conflict markers in place in the inner
+ conflict should have no practical impact, but it simplifies the
+ implementation.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
@@ -63,9 +65,11 @@
+~~~~~~~~~~~~~~~~
+
+Nested conflicts are handled very similarly to "simple" conflicts.
-+Same as before, labels on conflict markers and diff3 output is
-+stripped, and the conflict hunks are sorted, for both the outer and
-+the inner conflict.
++Similar to simple conflicts, the conflict is first normalized by
++stripping the labels from conflict markers, stripping the diff3
++output, and the sorting the conflict hunks, both for the outer and the
++inner conflict. This is done recursively, so any number of nested
++conflicts can be handled.
+
+The only difference is in how the conflict ID is calculated. For the
+inner conflict, the conflict markers themselves are not stripped out
@@ -83,16 +87,16 @@
+ >>>>>>> branch-2
+ >>>>>>> branch-3~
+
-+After stripping out the labels of the conflict markers, the conflict
-+would look as follows:
++After stripping out the labels of the conflict markers, and sorting
++the hunks, the conflict would look as follows:
+
+ <<<<<<<
+ 1
+ =======
+ <<<<<<<
-+ 3
-+ =======
+ 2
++ =======
++ 3
+ >>>>>>>
+ >>>>>>>
+
@@ -108,23 +112,21 @@
struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
- struct strbuf buf = STRBUF_INIT;
+ struct strbuf buf = STRBUF_INIT, conflict = STRBUF_INIT;
- int has_conflicts = 1;
+ int has_conflicts = -1;
+
while (!io->getline(&buf, io)) {
-- if (is_cmarker(buf.buf, '<', marker_size))
-- goto bad;
-- else if (is_cmarker(buf.buf, '|', marker_size)) {
-+ if (is_cmarker(buf.buf, '<', marker_size)) {
+ if (is_cmarker(buf.buf, '<', marker_size)) {
+- break;
+ if (handle_conflict(&conflict, io, marker_size, NULL) < 0)
-+ goto bad;
++ break;
+ if (hunk == RR_SIDE_1)
+ strbuf_addbuf(&one, &conflict);
+ else
+ strbuf_addbuf(&two, &conflict);
+ strbuf_release(&conflict);
-+ } else if (is_cmarker(buf.buf, '|', marker_size)) {
+ } else if (is_cmarker(buf.buf, '|', marker_size)) {
if (hunk != RR_SIDE_1)
- goto bad;
- hunk = RR_ORIGINAL;
+ break;
diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
--- a/t/t4200-rerere.sh
@@ -169,6 +171,5 @@
+ cat test >actual &&
+ test_cmp expect actual
+'
-+
+
test_done
10: 4b11dce7dd = 11: 35a826908f rerere: recalculate conflict ID when unresolved conflict is committedThomas Gummerer (11): rerere: unify error messages when read_cache fails rerere: lowercase error messages rerere: wrap paths in output in sq rerere: mark strings for translation rerere: add documentation for conflict normalization rerere: fix crash when conflict goes unresolved rerere: only return whether a path has conflicts or not rerere: factor out handle_conflict function rerere: return strbuf from handle path rerere: teach rerere to handle nested conflicts rerere: recalculate conflict ID when unresolved conflict is committed
Documentation/technical/rerere.txt | 182 +++++++++++++++++++++ builtin/rerere.c | 4 +- rerere.c | 243 ++++++++++++++--------------- t/t4200-rerere.sh | 66 ++++++++ 4 files changed, 366 insertions(+), 129 deletions(-) create mode 100644 Documentation/technical/rerere.txt
-- 2.18.0.233.g985f88cf7e