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[PATCH v2 5/7] built-in add -p: implement the "checkout" patch modes

From
Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date
Dec 21, 2019, 21:57 UTC
Message-ID
<b3672b35e694660a57ba1201ec79ecf561d27704.1576965436.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.174.v2.git.1576965436.gitgitgadget@gmail.com>
From: Johannes Schindelin <johannes.schindelin@gmx.de>

This patch teaches the built-in `git add -p` machinery all the tricks it needs to know in order to act as the work horse for `git checkout -p`.

Apart from the minor changes (slightly reworded messages, different `diff` and `apply --check` invocations), it requires a new function to actually apply the changes, as `git checkout -p` is a bit special in that respect: when the desired changes do not apply to the index, but apply to the work tree, Git does not fail straight away, but asks the user whether to apply the changes to the worktree at least.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 add-interactive.h |   1 +
 add-patch.c       | 138 ++++++++++++++++++++++++++++++++++++++++++++--
 builtin/add.c     |   5 +-
 3 files changed, 137 insertions(+), 7 deletions(-)
diff --git a/add-interactive.h b/add-interactive.h
index 1f6a61326e..77907f6e21 100644
--- a/add-interactive.h
+++ b/add-interactive.h
@@ -27,6 +27,7 @@ enum add_p_mode {
 	ADD_P_ADD,
 	ADD_P_STASH,
 	ADD_P_RESET,
+	ADD_P_CHECKOUT,
 };
 
 int run_add_p(struct repository *r, enum add_p_mode mode,
diff --git a/add-patch.c b/add-patch.c
index af0a86f0f7..ec5116c187 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -111,6 +111,71 @@ static struct patch_mode patch_mode_reset_nothead = {
 			"the file\n"),
 };
 
+static struct patch_mode patch_mode_checkout_index = {
+	.diff_cmd = { "diff-files", NULL },
+	.apply_args = { "-R", NULL },
+	.apply_check_args = { "-R", NULL },
+	.is_reverse = 1,
+	.prompt_mode = {
+		N_("Discard mode change from worktree [y,n,q,a,d%s,?]? "),
+		N_("Discard deletion from worktree [y,n,q,a,d%s,?]? "),
+		N_("Discard this hunk from worktree [y,n,q,a,d%s,?]? "),
+	},
+	.edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
+			     "will immediately be marked for discarding."),
+	.help_patch_text =
+		N_("y - discard this hunk from worktree\n"
+		   "n - do not discard this hunk from worktree\n"
+		   "q - quit; do not discard this hunk or any of the remaining "
+			"ones\n"
+		   "a - discard this hunk and all later hunks in the file\n"
+		   "d - do not discard this hunk or any of the later hunks in "
+			"the file\n"),
+};
+
+static struct patch_mode patch_mode_checkout_head = {
+	.diff_cmd = { "diff-index", NULL },
+	.apply_for_checkout = 1,
+	.apply_check_args = { "-R", NULL },
+	.is_reverse = 1,
+	.prompt_mode = {
+		N_("Discard mode change from index and worktree [y,n,q,a,d%s,?]? "),
+		N_("Discard deletion from index and worktree [y,n,q,a,d%s,?]? "),
+		N_("Discard this hunk from index and worktree [y,n,q,a,d%s,?]? "),
+	},
+	.edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
+			     "will immediately be marked for discarding."),
+	.help_patch_text =
+		N_("y - discard this hunk from index and worktree\n"
+		   "n - do not discard this hunk from index and worktree\n"
+		   "q - quit; do not discard this hunk or any of the remaining "
+			"ones\n"
+		   "a - discard this hunk and all later hunks in the file\n"
+		   "d - do not discard this hunk or any of the later hunks in "
+			"the file\n"),
+};
+
+static struct patch_mode patch_mode_checkout_nothead = {
+	.diff_cmd = { "diff-index", "-R", NULL },
+	.apply_for_checkout = 1,
+	.apply_check_args = { NULL },
+	.prompt_mode = {
+		N_("Apply mode change to index and worktree [y,n,q,a,d%s,?]? "),
+		N_("Apply deletion to index and worktree [y,n,q,a,d%s,?]? "),
+		N_("Apply this hunk to index and worktree [y,n,q,a,d%s,?]? "),
+	},
+	.edit_hunk_hint = N_("If the patch applies cleanly, the edited hunk "
+			     "will immediately be marked for applying."),
+	.help_patch_text =
+		N_("y - apply this hunk to index and worktree\n"
+		   "n - do not apply this hunk to index and worktree\n"
+		   "q - quit; do not apply this hunk or any of the remaining "
+			"ones\n"
+		   "a - apply this hunk and all later hunks in the file\n"
+		   "d - do not apply this hunk or any of the later hunks in "
+			"the file\n"),
+};
+
 struct hunk_header {
 	unsigned long old_offset, old_count, new_offset, new_count;
 	/*
@@ -1067,6 +1132,57 @@ static int edit_hunk_loop(struct add_p_state *s,
 	}
 }
 
+static int apply_for_checkout(struct add_p_state *s, struct strbuf *diff,
+			      int is_reverse)
+{
+	const char *reverse = is_reverse ? "-R" : NULL;
+	struct child_process check_index = CHILD_PROCESS_INIT;
+	struct child_process check_worktree = CHILD_PROCESS_INIT;
+	struct child_process apply_index = CHILD_PROCESS_INIT;
+	struct child_process apply_worktree = CHILD_PROCESS_INIT;
+	int applies_index, applies_worktree;
+
+	setup_child_process(s, &check_index,
+			    "apply", "--cached", "--check", reverse, NULL);
+	applies_index = !pipe_command(&check_index, diff->buf, diff->len,
+				      NULL, 0, NULL, 0);
+
+	setup_child_process(s, &check_worktree,
+			    "apply", "--check", reverse, NULL);
+	applies_worktree = !pipe_command(&check_worktree, diff->buf, diff->len,
+					 NULL, 0, NULL, 0);
+
+	if (applies_worktree && applies_index) {
+		setup_child_process(s, &apply_index,
+				    "apply", "--cached", reverse, NULL);
+		pipe_command(&apply_index, diff->buf, diff->len,
+			     NULL, 0, NULL, 0);
+
+		setup_child_process(s, &apply_worktree,
+				    "apply", reverse, NULL);
+		pipe_command(&apply_worktree, diff->buf, diff->len,
+			     NULL, 0, NULL, 0);
+
+		return 1;
+	}
+
+	if (!applies_index) {
+		err(s, _("The selected hunks do not apply to the index!"));
+		if (prompt_yesno(s, _("Apply them to the worktree "
+					  "anyway? ")) > 0) {
+			setup_child_process(s, &apply_worktree,
+					    "apply", reverse, NULL);
+			return pipe_command(&apply_worktree, diff->buf,
+					    diff->len, NULL, 0, NULL, 0);
+		}
+		err(s, _("Nothing was applied.\n"));
+	} else
+		/* As a last resort, show the diff to the user */
+		fwrite(diff->buf, diff->len, 1, stderr);
+
+	return 0;
+}
+
 #define SUMMARY_HEADER_WIDTH 20
 #define SUMMARY_LINE_WIDTH 80
 static void summarize_hunk(struct add_p_state *s, struct hunk *hunk,
@@ -1392,11 +1508,16 @@ static int patch_update_file(struct add_p_state *s,
 		reassemble_patch(s, file_diff, 0, &s->buf);
 
 		discard_index(s->s.r->index);
-		setup_child_process(s, &cp, "apply", NULL);
-		argv_array_pushv(&cp.args, s->mode->apply_args);
-		if (pipe_command(&cp, s->buf.buf, s->buf.len,
-				 NULL, 0, NULL, 0))
-			error(_("'git apply' failed"));
+		if (s->mode->apply_for_checkout)
+			apply_for_checkout(s, &s->buf,
+					   s->mode->is_reverse);
+		else {
+			setup_child_process(s, &cp, "apply", NULL);
+			argv_array_pushv(&cp.args, s->mode->apply_args);
+			if (pipe_command(&cp, s->buf.buf, s->buf.len,
+					 NULL, 0, NULL, 0))
+				error(_("'git apply' failed"));
+		}
 		if (!repo_read_index(s->s.r))
 			repo_refresh_and_write_index(s->s.r, REFRESH_QUIET, 0,
 						     1, NULL, NULL, NULL);
@@ -1423,6 +1544,13 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
 			s.mode = &patch_mode_reset_head;
 		else
 			s.mode = &patch_mode_reset_nothead;
+	} else if (mode == ADD_P_CHECKOUT) {
+		if (!revision)
+			s.mode = &patch_mode_checkout_index;
+		else if (!strcmp(revision, "HEAD"))
+			s.mode = &patch_mode_checkout_head;
+		else
+			s.mode = &patch_mode_checkout_nothead;
 	} else
 		s.mode = &patch_mode_add;
 	s.revision = revision;
diff --git a/builtin/add.c b/builtin/add.c
index fa8bf6b10a..191856b036 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -206,9 +206,10 @@ int run_add_interactive(const char *revision, const char *patch_mode,
 			mode = ADD_P_STASH;
 		else if (!strcmp(patch_mode, "--patch=reset"))
 			mode = ADD_P_RESET;
+		else if (!strcmp(patch_mode, "--patch=checkout"))
+			mode = ADD_P_CHECKOUT;
 		else
-			die("'%s' not yet supported in the built-in add -p",
-			    patch_mode);
+			die("'%s' not supported", patch_mode);
 
 		return !!run_add_p(the_repository, mode, revision, pathspec);
 	}

-- 
gitgitgadget
Previous: Johannes Schindelin via GitGitGadgetNext: Johannes Schindelin via GitGitGadget
Message 21 of 23 in “stash/reset/checkout -p: optionally use the add --patch backend written in pure C”
  1. 0/7 stash/reset/checkout -p: optionally use the add --patch backend written in pure CJohannes Schindelin via GitGitGadget, Dec 17, 2019
  2. 3/7 legacy stash -p: respect the add.interactive.usebuiltin settingJohannes Schindelin via GitGitGadget, Dec 17, 2019
  3. 1/7 built-in add -p: prepare for patch modes other than "stage"Johannes Schindelin via GitGitGadget, Dec 17, 2019
  4. Junio C HamanoDec 17, 2019
  5. Johannes SchindelinDec 21, 2019
  6. 2/7 built-in add -p: implement the "stash" and "reset" patch modesJohannes Schindelin via GitGitGadget, Dec 17, 2019
  7. Junio C HamanoDec 17, 2019
  8. Johannes SchindelinDec 21, 2019
  9. 4/7 built-in stash: use the built-in `git add -p` if so configuredJohannes Schindelin via GitGitGadget, Dec 17, 2019
  10. Junio C HamanoDec 17, 2019
  11. Johannes SchindelinDec 21, 2019
  12. 5/7 built-in add -p: implement the "checkout" patch modesJohannes Schindelin via GitGitGadget, Dec 17, 2019
  13. 7/7 commit --interactive: make it work with the built-in `add -i`Johannes Schindelin via GitGitGadget, Dec 17, 2019
  14. 6/7 built-in add -p: implement the "worktree" patch modesJohannes Schindelin via GitGitGadget, Dec 17, 2019
  15. Junio C HamanoDec 17, 2019
  16. 0/7 stash/reset/checkout -p: optionally use the add --patch backend written in pure CJohannes Schindelin via GitGitGadget, Dec 21, 2019
  17. 1/7 built-in add -p: prepare for patch modes other than "stage"Johannes Schindelin via GitGitGadget, Dec 21, 2019
  18. 3/7 legacy stash -p: respect the add.interactive.usebuiltin settingJohannes Schindelin via GitGitGadget, Dec 21, 2019
  19. 2/7 built-in add -p: implement the "stash" and "reset" patch modesJohannes Schindelin via GitGitGadget, Dec 21, 2019
  20. 7/7 commit --interactive: make it work with the built-in `add -i`Johannes Schindelin via GitGitGadget, Dec 21, 2019
  21. 5/7 built-in add -p: implement the "checkout" patch modesJohannes Schindelin via GitGitGadget, Dec 21, 2019
  22. 4/7 built-in stash: use the built-in `git add -p` if so configuredJohannes Schindelin via GitGitGadget, Dec 21, 2019
  23. 6/7 built-in add -p: implement the "worktree" patch modesJohannes Schindelin via GitGitGadget, Dec 21, 2019

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