apply: make it possible to silently apply

This changes 'int apply_verbosely' into 'enum apply_verbosity', and
changes the possible values of the variable from a bool to
a tristate.

The previous 'false' state is changed into 'verbosity_normal'.
The previous 'true' state is changed into 'verbosity_verbose'.

The new added state is 'verbosity_silent'. It should prevent
anything to be printed on both stderr and stdout.

This is needed because `git am` wants to first call apply
functionality silently, if it can then fall back on 3-way merge
in case of error.

Printing on stdout, and calls to warning() or error() are not
taken care of in this patch, as that will be done in following
patches.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 48 insertions, 24 deletions

diff --git a/apply.c b/apply.c
index ce09ed9..74b450e 100644
--- a/apply.c
+++ b/apply.c
@@ -125,8 +125,11 @@ int check_apply_state(struct apply_state *state, int force_apply)
 			return error(_("--3way outside a repository"));
 		state->check_index = 1;
 	}
-	if (state->apply_with_reject)
-		state->apply = state->apply_verbosely = 1;
+	if (state->apply_with_reject) {
+		state->apply = 1;
+		if (state->apply_verbosity == verbosity_normal)
+			state->apply_verbosity = verbosity_verbose;
+	}
 	if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
 		state->apply = 0;
 	if (state->check_index && is_not_gitdir)
@@ -1620,8 +1623,9 @@ static void record_ws_error(struct apply_state *state,
 		return;
 
 	err = whitespace_error_string(result);
-	fprintf(stderr, "%s:%d: %s.\n%.*s\n",
-		state->patch_input_file, linenr, err, len, line);
+	if (state->apply_verbosity > verbosity_silent)
+		fprintf(stderr, "%s:%d: %s.\n%.*s\n",
+			state->patch_input_file, linenr, err, len, line);
 	free(err);
 }
 
@@ -1816,7 +1820,7 @@ static int parse_single_patch(struct apply_state *state,
 		return error(_("new file %s depends on old contents"), patch->new_name);
 	if (0 < patch->is_delete && newlines)
 		return error(_("deleted file %s still has contents"), patch->old_name);
-	if (!patch->is_delete && !newlines && context)
+	if (!patch->is_delete && !newlines && context && state->apply_verbosity > verbosity_silent)
 		fprintf_ln(stderr,
 			   _("** warning: "
 			     "file %s becomes empty but is not deleted"),
@@ -2911,7 +2915,7 @@ static int apply_one_fragment(struct apply_state *state,
 			/* Ignore it, we already handled it */
 			break;
 		default:
-			if (state->apply_verbosely)
+			if (state->apply_verbosity > verbosity_normal)
 				error(_("invalid start of line: '%c'"), first);
 			applied_pos = -1;
 			goto out;
@@ -3026,7 +3030,7 @@ static int apply_one_fragment(struct apply_state *state,
 				state->apply = 0;
 		}
 
-		if (state->apply_verbosely && applied_pos != pos) {
+		if (state->apply_verbosity > verbosity_normal && applied_pos != pos) {
 			int offset = applied_pos - pos;
 			if (state->apply_in_reverse)
 				offset = 0 - offset;
@@ -3041,14 +3045,14 @@ static int apply_one_fragment(struct apply_state *state,
 		 * Warn if it was necessary to reduce the number
 		 * of context lines.
 		 */
-		if ((leading != frag->leading) ||
-		    (trailing != frag->trailing))
+		if ((leading != frag->leading ||
+		     trailing != frag->trailing) && state->apply_verbosity > verbosity_silent)
 			fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
 					     " to apply fragment at %d"),
 				   leading, trailing, applied_pos+1);
 		update_image(state, img, applied_pos, &preimage, &postimage);
 	} else {
-		if (state->apply_verbosely)
+		if (state->apply_verbosity > verbosity_normal)
 			error(_("while searching for:\n%.*s"),
 			      (int)(old - oldlines), oldlines);
 	}
@@ -3539,7 +3543,8 @@ static int try_threeway(struct apply_state *state,
 		 read_blob_object(&buf, pre_sha1, patch->old_mode))
 		return error("repository lacks the necessary blob to fall back on 3-way merge.");
 
-	fprintf(stderr, "Falling back to three-way merge...\n");
+	if (state->apply_verbosity > verbosity_silent)
+		fprintf(stderr, "Falling back to three-way merge...\n");
 
 	img = strbuf_detach(&buf, &len);
 	prepare_image(&tmp_image, img, len, 1);
@@ -3569,7 +3574,9 @@ static int try_threeway(struct apply_state *state,
 	status = three_way_merge(image, patch->new_name,
 				 pre_sha1, our_sha1, post_sha1);
 	if (status < 0) {
-		fprintf(stderr, "Failed to fall back on three-way merge...\n");
+		if (state->apply_verbosity > verbosity_silent)
+			fprintf(stderr,
+				"Failed to fall back on three-way merge...\n");
 		return status;
 	}
 
@@ -3581,9 +3588,15 @@ static int try_threeway(struct apply_state *state,
 			hashcpy(patch->threeway_stage[0].hash, pre_sha1);
 		hashcpy(patch->threeway_stage[1].hash, our_sha1);
 		hashcpy(patch->threeway_stage[2].hash, post_sha1);
-		fprintf(stderr, "Applied patch to '%s' with conflicts.\n", patch->new_name);
+		if (state->apply_verbosity > verbosity_silent)
+			fprintf(stderr,
+				"Applied patch to '%s' with conflicts.\n",
+				patch->new_name);
 	} else {
-		fprintf(stderr, "Applied patch to '%s' cleanly.\n", patch->new_name);
+		if (state->apply_verbosity > verbosity_silent)
+			fprintf(stderr,
+				"Applied patch to '%s' cleanly.\n",
+				patch->new_name);
 	}
 	return 0;
 }
@@ -3956,7 +3969,7 @@ static int check_patch_list(struct apply_state *state, struct patch *patch)
 	prepare_fn_table(state, patch);
 	while (patch) {
 		int res;
-		if (state->apply_verbosely)
+		if (state->apply_verbosity > verbosity_normal)
 			say_patch_name(stderr,
 				       _("Checking patch %s..."), patch);
 		res = check_patch(state, patch);
@@ -4472,7 +4485,7 @@ static int write_out_one_reject(struct apply_state *state, struct patch *patch)
 	}
 
 	if (!cnt) {
-		if (state->apply_verbosely)
+		if (state->apply_verbosity > verbosity_normal)
 			say_patch_name(stderr,
 				       _("Applied patch %s cleanly."), patch);
 		return 0;
@@ -4489,7 +4502,8 @@ static int write_out_one_reject(struct apply_state *state, struct patch *patch)
 			    "Applying patch %%s with %d rejects...",
 			    cnt),
 		    cnt);
-	say_patch_name(stderr, sb.buf, patch);
+	if (state->apply_verbosity > verbosity_silent)
+		say_patch_name(stderr, sb.buf, patch);
 	strbuf_release(&sb);
 
 	cnt = strlen(patch->new_name);
@@ -4516,10 +4530,12 @@ static int write_out_one_reject(struct apply_state *state, struct patch *patch)
 	     frag;
 	     cnt++, frag = frag->next) {
 		if (!frag->rejected) {
-			fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
+			if (state->apply_verbosity > verbosity_silent)
+				fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
 			continue;
 		}
-		fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
+		if (state->apply_verbosity > verbosity_silent)
+			fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
 		fprintf(rej, "%.*s", frag->size, frag->patch);
 		if (frag->patch[frag->size-1] != '\n')
 			fputc('\n', rej);
@@ -4568,8 +4584,10 @@ static int write_out_results(struct apply_state *state, struct patch *list)
 		struct string_list_item *item;
 
 		string_list_sort(&cpath);
-		for_each_string_list_item(item, &cpath)
-			fprintf(stderr, "U %s\n", item->string);
+		if (state->apply_verbosity > verbosity_silent) {
+			for_each_string_list_item(item, &cpath)
+				fprintf(stderr, "U %s\n", item->string);
+		}
 		string_list_clear(&cpath, 0);
 
 		rerere(0);
@@ -4626,7 +4644,7 @@ static int apply_patch(struct apply_state *state,
 			listp = &patch->next;
 		}
 		else {
-			if (state->apply_verbosely)
+			if (state->apply_verbosity > verbosity_normal)
 				say_patch_name(stderr, _("Skipped patch '%s'."), patch);
 			free_patch(patch);
 			skipped_patch++;
diff --git a/apply.h b/apply.h
index 51b983b..f015403 100644
--- a/apply.h
+++ b/apply.h
@@ -13,6 +13,12 @@ enum apply_ws_ignore {
 	ignore_ws_change
 };
 
+enum apply_verbosity {
+	verbosity_silent = -1,
+	verbosity_normal = 0,
+	verbosity_verbose = 1
+};
+
 /*
  * We need to keep track of how symlinks in the preimage are
  * manipulated by the patches.  A patch to add a/b/c where a/b
@@ -51,13 +57,13 @@ struct apply_state {
 	int allow_overlap;
 	int apply_in_reverse;
 	int apply_with_reject;
-	int apply_verbosely;
 	int no_add;
 	int threeway;
 	int unidiff_zero;
 	int unsafe_paths;
 
 	/* Other non boolean parameters */
+	enum apply_verbosity apply_verbosity;
 	const char *fake_ancestor;
 	const char *patch_input_file;
 	int line_termination;
diff --git a/builtin/apply.c b/builtin/apply.c
index 9c66474..7338701 100644
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -74,7 +74,7 @@ int cmd_apply(int argc, const char **argv, const char *prefix)
 			N_("leave the rejected hunks in corresponding *.rej files")),
 		OPT_BOOL(0, "allow-overlap", &state.allow_overlap,
 			N_("allow overlapping hunks")),
-		OPT__VERBOSE(&state.apply_verbosely, N_("be verbose")),
+		OPT__VERBOSE(&state.apply_verbosity, N_("be verbose")),
 		OPT_BIT(0, "inaccurate-eof", &options,
 			N_("tolerate incorrectly detected missing new-line at the end of file"),
 			APPLY_OPT_INACCURATE_EOF),