[PATCH v13 10/14] apply: change error_routine when silent

[Christian Couder <christian.couder@gmail.com>]

To avoid printing anything when applying with
`state->apply_verbosity == verbosity_silent`, let's save the
existing warn and error routines before applying, and let's
replace them with a routine that does nothing.

Then after applying, let's restore the saved routines.

Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 apply.c | 21 ++++++++++++++++++++-
 apply.h |  8 ++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/apply.c b/apply.c
index ddbb0a2..bf81b70 100644
--- a/apply.c
+++ b/apply.c
@@ -112,6 +112,11 @@ void clear_apply_state(struct apply_state *state)
 	/* &state->fn_table is cleared at the end of apply_patch() */
 }
 
+static void mute_routine(const char *bla, va_list params)
+{
+	/* do nothing */
+}
+
 int check_apply_state(struct apply_state *state, int force_apply)
 {
 	int is_not_gitdir = !startup_info->have_repository;
@@ -144,6 +149,13 @@ int check_apply_state(struct apply_state *state, int force_apply)
 	if (!state->lock_file)
 		return error("BUG: state->lock_file should not be NULL");
 
+	if (state->apply_verbosity <= verbosity_silent) {
+		state->saved_error_routine = get_error_routine();
+		state->saved_warn_routine = get_warn_routine();
+		set_error_routine(mute_routine);
+		set_warn_routine(mute_routine);
+	}
+
 	return 0;
 }
 
@@ -4864,7 +4876,7 @@ int apply_all_patches(struct apply_state *state,
 		state->newfd = -1;
 	}
 
-	return !!errs;
+	res = !!errs;
 
 end:
 	if (state->newfd >= 0) {
@@ -4872,5 +4884,12 @@ int apply_all_patches(struct apply_state *state,
 		state->newfd = -1;
 	}
 
+	if (state->apply_verbosity <= verbosity_silent) {
+		set_error_routine(state->saved_error_routine);
+		set_warn_routine(state->saved_warn_routine);
+	}
+
+	if (res > -1)
+		return res;
 	return (res == -1 ? 1 : 128);
 }
diff --git a/apply.h b/apply.h
index bd4eb6d..5cde641 100644
--- a/apply.h
+++ b/apply.h
@@ -94,6 +94,14 @@ struct apply_state {
 	 */
 	struct string_list fn_table;
 
+	/*
+	 * This is to save reporting routines before using
+	 * set_error_routine() or set_warn_routine() to install muting
+	 * routines when in verbosity_silent mode.
+	 */
+	void (*saved_error_routine)(const char *err, va_list params);
+	void (*saved_warn_routine)(const char *warn, va_list params);
+
 	/* These control whitespace errors */
 	enum apply_ws_error_action ws_error_action;
 	enum apply_ws_ignore ws_ignore_action;
-- 
2.9.2.770.g14ff7d2