[PATCH] advice: Add advice.scissors to suppress "do not modify or remove this line"

[Josh Triplett <josh@joshtriplett.org>]

The scissors line before the diff in a verbose commit, or above all the
comments when using --cleanup=scissors, has the following two lines of
explanation after it:

Do not modify or remove the line above.
Everything below it will be ignored.

This is useful advice for new users, but potentially redundant for
experienced users, who might instead appreciate seeing two more lines of
information in their editor.

Add advice.scissors to suppress that explanation.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
---
 Documentation/config/advice.txt | 5 +++++
 advice.c                        | 1 +
 advice.h                        | 1 +
 wt-status.c                     | 3 ++-
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/config/advice.txt b/Documentation/config/advice.txt
index c7ea70f2e2..33ab688b6c 100644
--- a/Documentation/config/advice.txt
+++ b/Documentation/config/advice.txt
@@ -104,6 +104,11 @@ advice.*::
 	rmHints::
 		In case of failure in the output of linkgit:git-rm[1],
 		show directions on how to proceed from the current state.
+	scissors::
+		Advice shown by linkgit:git-commit[1] in the commit message
+		opened in an editor, after a scissors line (containing >8),
+		saying not to remove the line and that everything after the line
+		will be ignored.
 	sequencerInUse::
 		Advice shown when a sequencer command is already in progress.
 	skippedCherryPicks::
diff --git a/advice.c b/advice.c
index 6e9098ff08..0588012562 100644
--- a/advice.c
+++ b/advice.c
@@ -71,6 +71,7 @@ static struct {
 	[ADVICE_RESET_NO_REFRESH_WARNING]		= { "resetNoRefresh" },
 	[ADVICE_RESOLVE_CONFLICT]			= { "resolveConflict" },
 	[ADVICE_RM_HINTS]				= { "rmHints" },
+	[ADVICE_SCISSORS]				= { "scissors" },
 	[ADVICE_SEQUENCER_IN_USE]			= { "sequencerInUse" },
 	[ADVICE_SET_UPSTREAM_FAILURE]			= { "setUpstreamFailure" },
 	[ADVICE_SKIPPED_CHERRY_PICKS]			= { "skippedCherryPicks" },
diff --git a/advice.h b/advice.h
index 9d4f49ae38..9725aa4199 100644
--- a/advice.h
+++ b/advice.h
@@ -39,6 +39,7 @@ enum advice_type {
 	ADVICE_RESET_NO_REFRESH_WARNING,
 	ADVICE_RESOLVE_CONFLICT,
 	ADVICE_RM_HINTS,
+	ADVICE_SCISSORS,
 	ADVICE_SEQUENCER_IN_USE,
 	ADVICE_SET_UPSTREAM_FAILURE,
 	ADVICE_SKIPPED_CHERRY_PICKS,
diff --git a/wt-status.c b/wt-status.c
index 459d399baa..19d4986351 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1104,7 +1104,8 @@ void wt_status_append_cut_line(struct strbuf *buf)
 	const char *explanation = _("Do not modify or remove the line above.\nEverything below it will be ignored.");
 
 	strbuf_commented_addf(buf, comment_line_char, "%s", cut_line);
-	strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
+	if (advice_enabled(ADVICE_SCISSORS))
+		strbuf_add_commented_lines(buf, explanation, strlen(explanation), comment_line_char);
 }
 
 void wt_status_add_cut_line(FILE *fp)
-- 
2.43.0