add-patch: allow disabling editing of hunks

The "add-patch" mode allows the user to edit hunks to apply custom
changes. This is incompatible with a new `git history split` command
that we're about to introduce in a subsequent commit, so we need a way
to disable this mode.

Add a new flag to disable editing hunks.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

7 files changed, 28 insertions, 15 deletions

diff --git a/add-interactive.c b/add-interactive.c
index 152e2a0297..3cf8a1dbf8 100644
--- a/add-interactive.c
+++ b/add-interactive.c
@@ -927,7 +927,7 @@ static int run_patch(struct add_i_state *s, const struct pathspec *ps,
 		parse_pathspec(&ps_selected,
 			       PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
 			       PATHSPEC_LITERAL_PATH, "", args.v);
-		res = run_add_p(s->r, ADD_P_ADD, &opts, NULL, &ps_selected);
+		res = run_add_p(s->r, ADD_P_ADD, &opts, NULL, &ps_selected, 0);
 		strvec_clear(&args);
 		clear_pathspec(&ps_selected);
 	}
diff --git a/add-patch.c b/add-patch.c
index b4dc7d2293..4e28e5c187 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1604,7 +1604,9 @@ static bool get_first_undecided(const struct file_diff *file_diff, size_t *idx)
 	return false;
 }
 
-static size_t patch_update_file(struct add_p_state *s, size_t idx)
+static size_t patch_update_file(struct add_p_state *s,
+				size_t idx,
+				unsigned flags)
 {
 	size_t hunk_index = 0;
 	ssize_t i, undecided_previous, undecided_next, rendered_hunk_index = -1;
@@ -1715,7 +1717,8 @@ static size_t patch_update_file(struct add_p_state *s, size_t idx)
 				permitted |= ALLOW_SPLIT;
 				strbuf_addstr(&s->buf, ",s");
 			}
-			if (hunk_index + 1 > file_diff->mode_change &&
+			if (!(flags & ADD_P_DISALLOW_EDIT) &&
+			    hunk_index + 1 > file_diff->mode_change &&
 			    !file_diff->deleted) {
 				permitted |= ALLOW_EDIT;
 				strbuf_addstr(&s->buf, ",e");
@@ -2003,7 +2006,8 @@ soft_increment:
 }
 
 static int run_add_p_common(struct add_p_state *state,
-			    const struct pathspec *ps)
+			    const struct pathspec *ps,
+			    unsigned flags)
 {
 	size_t binary_count = 0;
 	size_t i;
@@ -2017,7 +2021,7 @@ static int run_add_p_common(struct add_p_state *state,
 			i++;
 			continue;
 		}
-		if ((i = patch_update_file(state, i)) == state->file_diff_nr)
+		if ((i = patch_update_file(state, i, flags)) == state->file_diff_nr)
 			break;
 	}
 
@@ -2035,7 +2039,8 @@ static int run_add_p_common(struct add_p_state *state,
 
 int run_add_p(struct repository *r, enum add_p_mode mode,
 	      struct interactive_options *opts, const char *revision,
-	      const struct pathspec *ps)
+	      const struct pathspec *ps,
+	      unsigned flags)
 {
 	struct add_p_state s = {
 		.r = r,
@@ -2084,7 +2089,7 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
 		goto out;
 	}
 
-	ret = run_add_p_common(&s, ps);
+	ret = run_add_p_common(&s, ps, flags);
 	if (ret < 0)
 		goto out;
 
@@ -2100,7 +2105,8 @@ int run_add_p_index(struct repository *r,
 		    const char *index_file,
 		    struct interactive_options *opts,
 		    const char *revision,
-		    const struct pathspec *ps)
+		    const struct pathspec *ps,
+		    unsigned flags)
 {
 	struct patch_mode mode = {
 		.apply_args = { "--cached", NULL },
@@ -2156,7 +2162,7 @@ int run_add_p_index(struct repository *r,
 	mode.diff_cmd[1] = "-r";
 	mode.diff_cmd[2] = parent_tree_oid;
 
-	ret = run_add_p_common(&s, ps);
+	ret = run_add_p_common(&s, ps, flags);
 	if (ret < 0)
 		goto out;
 
diff --git a/add-patch.h b/add-patch.h
index cf2a31a40f..fb6d975b68 100644
--- a/add-patch.h
+++ b/add-patch.h
@@ -53,15 +53,22 @@ enum add_p_mode {
 	ADD_P_WORKTREE,
 };
 
+enum add_p_flags {
+	/* Disallow "editing" hunks. */
+	ADD_P_DISALLOW_EDIT = (1 << 0),
+};
+
 int run_add_p(struct repository *r, enum add_p_mode mode,
 	      struct interactive_options *opts, const char *revision,
-	      const struct pathspec *ps);
+	      const struct pathspec *ps,
+	      unsigned flags);
 
 int run_add_p_index(struct repository *r,
 		    struct index_state *index,
 		    const char *index_file,
 		    struct interactive_options *opts,
 		    const char *revision,
-		    const struct pathspec *ps);
+		    const struct pathspec *ps,
+		    unsigned flags);
 
 #endif
diff --git a/builtin/add.c b/builtin/add.c
index 84f9bcb789..eeab779328 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -172,7 +172,7 @@ int interactive_add(struct repository *repo,
 		       prefix, argv);
 
 	if (patch)
-		ret = !!run_add_p(repo, ADD_P_ADD, interactive_opts, NULL, &pathspec);
+		ret = !!run_add_p(repo, ADD_P_ADD, interactive_opts, NULL, &pathspec, 0);
 	else
 		ret = !!run_add_i(repo, &pathspec, interactive_opts);
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
index bebe18c1d9..a8863277f2 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -563,7 +563,7 @@ static int checkout_paths(const struct checkout_opts *opts,
 			BUG("either flag must have been set, worktree=%d, index=%d",
 			    opts->checkout_worktree, opts->checkout_index);
 		return !!run_add_p(the_repository, patch_mode, &interactive_opts,
-				   rev, &opts->pathspec);
+				   rev, &opts->pathspec, 0);
 	}
 
 	repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);
diff --git a/builtin/reset.c b/builtin/reset.c
index 4a74a82c0a..3590be57a5 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -438,7 +438,7 @@ int cmd_reset(int argc,
 			die(_("options '%s' and '%s' cannot be used together"), "--patch", "--{hard,mixed,soft}");
 		trace2_cmd_mode("patch-interactive");
 		update_ref_status = !!run_add_p(the_repository, ADD_P_RESET,
-						&interactive_opts, rev, &pathspec);
+						&interactive_opts, rev, &pathspec, 0);
 		goto cleanup;
 	} else {
 		if (interactive_opts.context != -1)
diff --git a/builtin/stash.c b/builtin/stash.c
index c467c02c7f..7c68a1d7f9 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -1331,7 +1331,7 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 	old_index_env = xstrdup_or_null(getenv(INDEX_ENVIRONMENT));
 	setenv(INDEX_ENVIRONMENT, the_repository->index_file, 1);
 
-	ret = !!run_add_p(the_repository, ADD_P_STASH, interactive_opts, NULL, ps);
+	ret = !!run_add_p(the_repository, ADD_P_STASH, interactive_opts, NULL, ps, 0);
 
 	the_repository->index_file = old_repo_index_file;
 	if (old_index_env && *old_index_env)