rebase -i: add --ignore-whitespace flag

Rebase is implemented with two different backends - 'apply' and
'merge' each of which support a different set of options. In
particular the apply backend supports a number of options implemented
by 'git am' that are not implemented in the merge backend. This means
that the available options are different depending on which backend is
used which is confusing. This patch adds support for the
--ignore-whitespace option to the merge backend. This option treats
lines with only whitespace changes as unchanged and is implemented in
the merge backend by translating it to -Xignore-space-change.

Signed-off-by: Rohit Ashiwal <rohit.ashiwal265@gmail.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index f7a6033607fa558dfd5a0437d7b4327ff1c44c78..b003784f019b6c64d9298a7991f4a7a70d9eceb6 100644 (file)
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -422,8 +422,23 @@ your branch contains commits which were dropped, this option can be used
 with `--keep-base` in order to drop those commits from your branch.
 
 --ignore-whitespace::
+       Ignore whitespace differences when trying to reconcile
+differences. Currently, each backend implements an approximation of
+this behavior:
++
+apply backend: When applying a patch, ignore changes in whitespace in
+context lines. Unfortunately, this means that if the "old" lines being
+replaced by the patch differ only in whitespace from the existing
+file, you will get a merge conflict instead of a successful patch
+application.
++
+merge backend: Treat lines with only whitespace changes as unchanged
+when merging. Unfortunately, this means that any patch hunks that were
+intended to modify whitespace and nothing else will be dropped, even
+if the other side had no changes that conflicted.
+
 --whitespace=<option>::
-       These flags are passed to the 'git apply' program
+       This flag is passed to the 'git apply' program
        (see linkgit:git-apply[1]) that applies the patch.
        Implies --apply.
 +
@@ -572,7 +587,6 @@ The following options:
  * --apply
  * --committer-date-is-author-date
  * --ignore-date
- * --ignore-whitespace
  * --whitespace
  * -C
 
@@ -598,6 +612,7 @@ In addition, the following pairs of options are incompatible:
  * --preserve-merges and --signoff
  * --preserve-merges and --rebase-merges
  * --preserve-merges and --empty=
+ * --preserve-merges and --ignore-whitespace
  * --keep-base and --onto
  * --keep-base and --root
 

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 27a07d4e78e63855a80b259f640f87c276c8e2c3..bd93e9742cd490f4aa5b88fcff9cfbc7161b0820 100644 (file)
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -126,6 +126,7 @@ static struct replay_opts get_replay_opts(const struct rebase_options *opts)
        replay.reschedule_failed_exec = opts->reschedule_failed_exec;
        replay.gpg_sign = xstrdup_or_null(opts->gpg_sign_opt);
        replay.strategy = opts->strategy;
+
        if (opts->strategy_opts)
                parse_strategy_opts(&replay, opts->strategy_opts);
 
@@ -1466,6 +1467,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        struct strbuf revisions = STRBUF_INIT;
        struct strbuf buf = STRBUF_INIT;
        struct object_id merge_base;
+       int ignore_whitespace = 0;
        enum action action = ACTION_NONE;
        const char *gpg_sign = NULL;
        struct string_list exec = STRING_LIST_INIT_NODUP;
@@ -1495,9 +1497,6 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                        PARSE_OPT_NOARG, NULL, REBASE_DIFFSTAT },
                OPT_BOOL(0, "signoff", &options.signoff,
                         N_("add a Signed-off-by: line to each commit")),
-               OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &options.git_am_opts,
-                                 NULL, N_("passed to 'git am'"),
-                                 PARSE_OPT_NOARG),
                OPT_PASSTHRU_ARGV(0, "committer-date-is-author-date",
                                  &options.git_am_opts, NULL,
                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
@@ -1505,6 +1504,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                                  N_("passed to 'git am'"), PARSE_OPT_NOARG),
                OPT_PASSTHRU_ARGV('C', NULL, &options.git_am_opts, N_("n"),
                                  N_("passed to 'git apply'"), 0),
+               OPT_BOOL(0, "ignore-whitespace", &ignore_whitespace,
+                        N_("ignore changes in whitespace")),
                OPT_PASSTHRU_ARGV(0, "whitespace", &options.git_am_opts,
                                  N_("action"), N_("passed to 'git apply'"), 0),
                OPT_BIT('f', "force-rebase", &options.flags,
@@ -1850,6 +1851,18 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
                imply_merge(&options, "--rebase-merges");
        }
 
+       if (options.type == REBASE_APPLY) {
+               if (ignore_whitespace)
+                       argv_array_push(&options.git_am_opts,
+                                       "--ignore-whitespace");
+       } else {
+               /* REBASE_MERGE and PRESERVE_MERGES */
+               if (ignore_whitespace) {
+                       string_list_append(&strategy_options,
+                                          "ignore-space-change");
+               }
+       }
+
        if (strategy_options.nr) {
                int i;
 

diff --git a/t/t3422-rebase-incompatible-options.sh b/t/t3422-rebase-incompatible-options.sh
index 50e7960702da4fa0306818f305f5d735f2292f53..55ca46786da75fab0d8193a900dff7e6d3bf4e4b 100755 (executable)
--- a/t/t3422-rebase-incompatible-options.sh
+++ b/t/t3422-rebase-incompatible-options.sh
@@ -61,7 +61,6 @@ test_rebase_am_only () {
 }
 
 test_rebase_am_only --whitespace=fix
-test_rebase_am_only --ignore-whitespace
 test_rebase_am_only --committer-date-is-author-date
 test_rebase_am_only -C4
 

diff --git a/t/t3436-rebase-more-options.sh b/t/t3436-rebase-more-options.sh
new file mode 100755 (executable)
index 0000000..4f8a6e5
--- /dev/null
+++ b/t/t3436-rebase-more-options.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+#
+# Copyright (c) 2019 Rohit Ashiwal
+#
+
+test_description='tests to ensure compatibility between am and interactive backends'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+# This is a special case in which both am and interactive backends
+# provide the same output. It was done intentionally because
+# both the backends fall short of optimal behaviour.
+test_expect_success 'setup' '
+       git checkout -b topic &&
+       test_write_lines "line 1" "     line 2" "line 3" >file &&
+       git add file &&
+       git commit -m "add file" &&
+
+       test_write_lines "line 1" "new line 2" "line 3" >file &&
+       git commit -am "update file" &&
+       git tag side &&
+
+       git checkout --orphan master &&
+       test_write_lines "line 1" "        line 2" "line 3" >file &&
+       git commit -am "add file" &&
+       git tag main
+'
+
+test_expect_success '--ignore-whitespace works with apply backend' '
+       test_must_fail git rebase --apply main side &&
+       git rebase --abort &&
+       git rebase --apply --ignore-whitespace main side &&
+       git diff --exit-code side
+'
+
+test_expect_success '--ignore-whitespace works with merge backend' '
+       test_must_fail git rebase --merge main side &&
+       git rebase --abort &&
+       git rebase --merge --ignore-whitespace main side &&
+       git diff --exit-code side
+'
+
+test_expect_success '--ignore-whitespace is remembered when continuing' '
+       (
+               set_fake_editor &&
+               FAKE_LINES="break 1" git rebase -i --ignore-whitespace \
+                       main side &&
+               git rebase --continue
+       ) &&
+       git diff --exit-code side
+'
+
+# This must be the last test in this file
+test_expect_success '$EDITOR and friends are unchanged' '
+       test_editor_unchanged
+'
+
+test_done