[PATCH 0/6] Improve "git log --graph" output of merges

[PATCH 0/6] Improve "git log --graph" output of merges

[John Keeping]

This series changes a couple of places that do not currently indent
their output when being shown with a graph.

The first patch was already posted [1] and addresses the output of "git
log --graph -c -p".  Patch 2 is an independent fix I noticed while
working on the later patches.

Patches 3-5 introduce a helper function and change existing sites using
diff_options->output_prefix to use it, resulting in a net reduction by
about 60 lines.  There is no functional change here.

The final patch uses the helper introduced in patch 4 to make combined
diffs should the output prefix before each line.  This affects the
output of "git log --graph --cc [-p|--raw]".

[1] http://article.gmane.org/gmane.comp.version-control.git/215630

John Keeping (6):
  graph: output padding for merge subsequent parents
  diff: write prefix to the correct file
  diff.c: make constant string arguments const
  diff: add diff_line_prefix function
  diff.c: use diff_line_prefix() where applicable
  combine-diff.c: teach combined diffs about line prefix

 combine-diff.c |  47 +++++++++++++--------
 diff.c         | 131 +++++++++++++++------------------------------------------
 diff.h         |   3 ++
 graph.c        |  10 +++++
 4 files changed, 77 insertions(+), 114 deletions(-)

-- 
1.8.1.2

[PATCH 1/6] graph: output padding for merge subsequent parents

[John Keeping]

When showing merges in git-log, the same commit is shown once for each
parent.  Combined with "--graph" this results in graph_show_commit()
being called once for each parent without graph_update() being called.

Currently graph_show_commit() does not print anything on subsequent
invocations for the same commit (this was changed by commit 656197a -
"graph.c: infinite loop in git whatchanged --graph -m" from the previous
behaviour of looping infinitely).

Change this so that if the graph code believes it has already shown the
commit it prints a single padding line.

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 graph.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/graph.c b/graph.c
index 391a712..2a3fc5c 100644
--- a/graph.c
+++ b/graph.c
@@ -1227,6 +1227,16 @@ void graph_show_commit(struct git_graph *graph)
 	if (!graph)
 		return;
 
+	/*
+	 * When showing a diff of a merge against each of its parents, we
+	 * are called once for each parent without graph_update having been
+	 * called.  In this case, simply output a single padding line.
+	 */
+	if (graph_is_commit_finished(graph)) {
+		graph_show_padding(graph);
+		shown_commit_line = 1;
+	}
+
 	while (!shown_commit_line && !graph_is_commit_finished(graph)) {
 		shown_commit_line = graph_next_line(graph, &msgbuf);
 		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
-- 
1.8.1.2

[PATCH 2/6] diff: write prefix to the correct file

[John Keeping]

Write the prefix for an output line to the same file as the actual
content.

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 diff.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/diff.c b/diff.c
index 348f71b..bf95235 100644
--- a/diff.c
+++ b/diff.c
@@ -4485,7 +4485,7 @@ void diff_flush(struct diff_options *options)
 				struct strbuf *msg = NULL;
 				msg = options->output_prefix(options,
 					options->output_prefix_data);
-				fwrite(msg->buf, msg->len, 1, stdout);
+				fwrite(msg->buf, msg->len, 1, options->file);
 			}
 			putc(options->line_termination, options->file);
 			if (options->stat_sep) {
-- 
1.8.1.2

[PATCH 3/6] diff.c: make constant string arguments const

[John Keeping]

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 diff.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/diff.c b/diff.c
index bf95235..73ae02d 100644
--- a/diff.c
+++ b/diff.c
@@ -2123,7 +2123,8 @@ static unsigned char *deflate_it(char *data,
 	return deflated;
 }
 
-static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
+static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
+				  const char *prefix)
 {
 	void *cp;
 	void *delta;
@@ -2184,7 +2185,8 @@ static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char
 	free(data);
 }
 
-static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
+static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
+			     const char *prefix)
 {
 	fprintf(file, "%sGIT binary patch\n", prefix);
 	emit_binary_diff_body(file, one, two, prefix);
-- 
1.8.1.2

[PATCH 4/6] diff: add diff_line_prefix function

[John Keeping]

This is a helper function to call the diff output_prefix function and
return its value as a C string, allowing us to greatly simplify
everywhere that needs to get the output prefix.

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 diff.c | 10 ++++++++++
 diff.h |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/diff.c b/diff.c
index 73ae02d..ed14d5d 100644
--- a/diff.c
+++ b/diff.c
@@ -1105,6 +1105,16 @@ const char *diff_get_color(int diff_use_color, enum color_diff ix)
 	return "";
 }
 
+const char *diff_line_prefix(struct diff_options *opt)
+{
+	struct strbuf *msgbuf;
+	if (!opt->output_prefix)
+		return "";
+
+	msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
+	return msgbuf->buf;
+}
+
 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 {
 	const char *cp;
diff --git a/diff.h b/diff.h
index a47bae4..76830e2 100644
--- a/diff.h
+++ b/diff.h
@@ -174,6 +174,9 @@ const char *diff_get_color(int diff_use_color, enum color_diff ix);
 	diff_get_color((o)->use_color, ix)
 
 
+const char *diff_line_prefix(struct diff_options *);
+
+
 extern const char mime_boundary_leader[];
 
 extern void diff_tree_setup_paths(const char **paths, struct diff_options *);
-- 
1.8.1.2

[PATCH 5/6] diff.c: use diff_line_prefix() where applicable

[John Keeping]

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 diff.c | 115 ++++++++++++-----------------------------------------------------
 1 file changed, 20 insertions(+), 95 deletions(-)

diff --git a/diff.c b/diff.c
index ed14d5d..f441f6c 100644
--- a/diff.c
+++ b/diff.c
@@ -402,12 +402,7 @@ static void emit_line_0(struct diff_options *o, const char *set, const char *res
 	int nofirst;
 	FILE *file = o->file;
 
-	if (o->output_prefix) {
-		struct strbuf *msg = NULL;
-		msg = o->output_prefix(o, o->output_prefix_data);
-		assert(msg);
-		fwrite(msg->buf, msg->len, 1, file);
-	}
+	fputs(diff_line_prefix(o), file);
 
 	if (len == 0) {
 		has_trailing_newline = (first == '\n');
@@ -625,13 +620,7 @@ static void emit_rewrite_diff(const char *name_a,
 	char *data_one, *data_two;
 	size_t size_one, size_two;
 	struct emit_callback ecbdata;
-	char *line_prefix = "";
-	struct strbuf *msgbuf;
-
-	if (o && o->output_prefix) {
-		msgbuf = o->output_prefix(o, o->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
+	const char *line_prefix = diff_line_prefix(o);
 
 	if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 		a_prefix = o->b_prefix;
@@ -827,18 +816,14 @@ static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 	int minus_first, minus_len, plus_first, plus_len;
 	const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 	struct diff_options *opt = diff_words->opt;
-	struct strbuf *msgbuf;
-	char *line_prefix = "";
+	const char *line_prefix;
 
 	if (line[0] != '@' || parse_hunk_header(line, len,
 			&minus_first, &minus_len, &plus_first, &plus_len))
 		return;
 
 	assert(opt);
-	if (opt->output_prefix) {
-		msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
+	line_prefix = diff_line_prefix(opt);
 
 	/* POSIX requires that first be decremented by one if len == 0... */
 	if (minus_len) {
@@ -962,14 +947,10 @@ static void diff_words_show(struct diff_words_data *diff_words)
 	struct diff_words_style *style = diff_words->style;
 
 	struct diff_options *opt = diff_words->opt;
-	struct strbuf *msgbuf;
-	char *line_prefix = "";
+	const char *line_prefix;
 
 	assert(opt);
-	if (opt->output_prefix) {
-		msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
+	line_prefix = diff_line_prefix(opt);
 
 	/* special case: only removal */
 	if (!diff_words->plus.text.size) {
@@ -1155,13 +1136,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
 	const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 	const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 	struct diff_options *o = ecbdata->opt;
-	char *line_prefix = "";
-	struct strbuf *msgbuf;
-
-	if (o && o->output_prefix) {
-		msgbuf = o->output_prefix(o, o->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
+	const char *line_prefix = diff_line_prefix(o);
 
 	if (ecbdata->header) {
 		fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
@@ -1485,16 +1460,11 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
 	const char *reset, *add_c, *del_c;
 	const char *line_prefix = "";
 	int extra_shown = 0;
-	struct strbuf *msg = NULL;
 
 	if (data->nr == 0)
 		return;
 
-	if (options->output_prefix) {
-		msg = options->output_prefix(options, options->output_prefix_data);
-		line_prefix = msg->buf;
-	}
-
+	line_prefix = diff_line_prefix(options);
 	count = options->stat_count ? options->stat_count : data->nr;
 
 	reset = diff_get_color_opt(options, DIFF_RESET);
@@ -1746,12 +1716,7 @@ static void show_shortstats(struct diffstat_t *data, struct diff_options *option
 			dels += deleted;
 		}
 	}
-	if (options->output_prefix) {
-		struct strbuf *msg = NULL;
-		msg = options->output_prefix(options,
-				options->output_prefix_data);
-		fprintf(options->file, "%s", msg->buf);
-	}
+	fprintf(options->file, "%s", diff_line_prefix(options));
 	print_stat_summary(options->file, total_files, adds, dels);
 }
 
@@ -1765,12 +1730,7 @@ static void show_numstat(struct diffstat_t *data, struct diff_options *options)
 	for (i = 0; i < data->nr; i++) {
 		struct diffstat_file *file = data->files[i];
 
-		if (options->output_prefix) {
-			struct strbuf *msg = NULL;
-			msg = options->output_prefix(options,
-					options->output_prefix_data);
-			fprintf(options->file, "%s", msg->buf);
-		}
+		fprintf(options->file, "%s", diff_line_prefix(options));
 
 		if (file->is_binary)
 			fprintf(options->file, "-\t-\t");
@@ -1812,13 +1772,7 @@ static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
 {
 	unsigned long this_dir = 0;
 	unsigned int sources = 0;
-	const char *line_prefix = "";
-	struct strbuf *msg = NULL;
-
-	if (opt->output_prefix) {
-		msg = opt->output_prefix(opt, opt->output_prefix_data);
-		line_prefix = msg->buf;
-	}
+	const char *line_prefix = diff_line_prefix(opt);
 
 	while (dir->nr) {
 		struct dirstat_file *f = dir->files;
@@ -2068,15 +2022,10 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
 	const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
 	const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
 	char *err;
-	char *line_prefix = "";
-	struct strbuf *msgbuf;
+	const char *line_prefix;
 
 	assert(data->o);
-	if (data->o->output_prefix) {
-		msgbuf = data->o->output_prefix(data->o,
-			data->o->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
+	line_prefix = diff_line_prefix(data->o);
 
 	if (line[0] == '+') {
 		unsigned bad;
@@ -2263,13 +2212,7 @@ static void builtin_diff(const char *name_a,
 	struct userdiff_driver *textconv_one = NULL;
 	struct userdiff_driver *textconv_two = NULL;
 	struct strbuf header = STRBUF_INIT;
-	struct strbuf *msgbuf;
-	char *line_prefix = "";
-
-	if (o->output_prefix) {
-		msgbuf = o->output_prefix(o, o->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
+	const char *line_prefix = diff_line_prefix(o);
 
 	if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
 			(!one->mode || S_ISGITLINK(one->mode)) &&
@@ -2968,14 +2911,9 @@ static void fill_metainfo(struct strbuf *msg,
 {
 	const char *set = diff_get_color(use_color, DIFF_METAINFO);
 	const char *reset = diff_get_color(use_color, DIFF_RESET);
-	struct strbuf *msgbuf;
-	char *line_prefix = "";
+	const char *line_prefix = diff_line_prefix(o);
 
 	*must_show_header = 1;
-	if (o->output_prefix) {
-		msgbuf = o->output_prefix(o, o->output_prefix_data);
-		line_prefix = msgbuf->buf;
-	}
 	strbuf_init(msg, PATH_MAX * 2 + 300);
 	switch (p->status) {
 	case DIFF_STATUS_COPIED:
@@ -3912,12 +3850,8 @@ static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
 {
 	int line_termination = opt->line_termination;
 	int inter_name_termination = line_termination ? '\t' : '\0';
-	if (opt->output_prefix) {
-		struct strbuf *msg = NULL;
-		msg = opt->output_prefix(opt, opt->output_prefix_data);
-		fprintf(opt->file, "%s", msg->buf);
-	}
 
+	fprintf(opt->file, "%s", diff_line_prefix(opt));
 	if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
 		fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
 			diff_unique_abbrev(p->one->sha1, opt->abbrev));
@@ -4187,12 +4121,7 @@ static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_fil
 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
 {
 	FILE *file = opt->file;
-	char *line_prefix = "";
-
-	if (opt->output_prefix) {
-		struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
-		line_prefix = buf->buf;
-	}
+	const char *line_prefix = diff_line_prefix(opt);
 
 	switch(p->status) {
 	case DIFF_STATUS_DELETED:
@@ -4493,13 +4422,9 @@ void diff_flush(struct diff_options *options)
 
 	if (output_format & DIFF_FORMAT_PATCH) {
 		if (separator) {
-			if (options->output_prefix) {
-				struct strbuf *msg = NULL;
-				msg = options->output_prefix(options,
-					options->output_prefix_data);
-				fwrite(msg->buf, msg->len, 1, options->file);
-			}
-			putc(options->line_termination, options->file);
+			fprintf(options->file, "%s%c",
+				diff_line_prefix(options),
+				options->line_termination);
 			if (options->stat_sep) {
 				/* attach patch instead of inline */
 				fputs(options->stat_sep, options->file);
-- 
1.8.1.2

[PATCH 6/6] combine-diff.c: teach combined diffs about line prefix

[John Keeping]

When running "git log --graph --cc -p" the diff output for merges is not
indented by the graph structure, unlike the diffs of non-merge commits
(added in commit 7be5761 - diff.c: Output the text graph padding before
each diff line).

Fix this by teaching the combined diff code to output diff_line_prefix()
before each line.

Signed-off-by: John Keeping <john@keeping.me.uk>
---
 combine-diff.c | 47 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/combine-diff.c b/combine-diff.c
index bb1cc96..35c817b 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -526,7 +526,8 @@ static void show_line_to_eol(const char *line, int len, const char *reset)
 	       saw_cr_at_eol ? "\r" : "");
 }
 
-static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
+static void dump_sline(struct sline *sline, const char *line_prefix,
+		       unsigned long cnt, int num_parent,
 		       int use_color, int result_deleted)
 {
 	unsigned long mark = (1UL<<num_parent);
@@ -582,7 +583,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 			rlines -= null_context;
 		}
 
-		fputs(c_frag, stdout);
+		printf("%s%s", line_prefix, c_frag);
 		for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 		for (i = 0; i < num_parent; i++)
 			show_parent_lno(sline, lno, hunk_end, i, null_context);
@@ -614,7 +615,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 			struct sline *sl = &sline[lno++];
 			ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 			while (ll) {
-				fputs(c_old, stdout);
+				printf("%s%s", line_prefix, c_old);
 				for (j = 0; j < num_parent; j++) {
 					if (ll->parent_map & (1UL<<j))
 						putchar('-');
@@ -627,6 +628,7 @@ static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 			if (cnt < lno)
 				break;
 			p_mask = 1;
+			fputs(line_prefix, stdout);
 			if (!(sl->flag & (mark-1))) {
 				/*
 				 * This sline was here to hang the
@@ -680,11 +682,13 @@ static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 static void dump_quoted_path(const char *head,
 			     const char *prefix,
 			     const char *path,
+			     const char *line_prefix,
 			     const char *c_meta, const char *c_reset)
 {
 	static struct strbuf buf = STRBUF_INIT;
 
 	strbuf_reset(&buf);
+	strbuf_addstr(&buf, line_prefix);
 	strbuf_addstr(&buf, c_meta);
 	strbuf_addstr(&buf, head);
 	quote_two_c_style(&buf, prefix, path, 0);
@@ -696,6 +700,7 @@ static void show_combined_header(struct combine_diff_path *elem,
 				 int num_parent,
 				 int dense,
 				 struct rev_info *rev,
+				 const char *line_prefix,
 				 int mode_differs,
 				 int show_file_header)
 {
@@ -714,8 +719,8 @@ static void show_combined_header(struct combine_diff_path *elem,
 		show_log(rev);
 
 	dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
-			 "", elem->path, c_meta, c_reset);
-	printf("%sindex ", c_meta);
+			 "", elem->path, line_prefix, c_meta, c_reset);
+	printf("%s%sindex ", line_prefix, c_meta);
 	for (i = 0; i < num_parent; i++) {
 		abb = find_unique_abbrev(elem->parent[i].sha1,
 					 abbrev);
@@ -734,11 +739,12 @@ static void show_combined_header(struct combine_diff_path *elem,
 			    DIFF_STATUS_ADDED)
 				added = 0;
 		if (added)
-			printf("%snew file mode %06o",
-			       c_meta, elem->mode);
+			printf("%s%snew file mode %06o",
+			       line_prefix, c_meta, elem->mode);
 		else {
 			if (deleted)
-				printf("%sdeleted file ", c_meta);
+				printf("%s%sdeleted file ",
+				       line_prefix, c_meta);
 			printf("mode ");
 			for (i = 0; i < num_parent; i++) {
 				printf("%s%06o", i ? "," : "",
@@ -755,16 +761,16 @@ static void show_combined_header(struct combine_diff_path *elem,
 
 	if (added)
 		dump_quoted_path("--- ", "", "/dev/null",
-				 c_meta, c_reset);
+				 line_prefix, c_meta, c_reset);
 	else
 		dump_quoted_path("--- ", a_prefix, elem->path,
-				 c_meta, c_reset);
+				 line_prefix, c_meta, c_reset);
 	if (deleted)
 		dump_quoted_path("+++ ", "", "/dev/null",
-				 c_meta, c_reset);
+				 line_prefix, c_meta, c_reset);
 	else
 		dump_quoted_path("+++ ", b_prefix, elem->path,
-				 c_meta, c_reset);
+				 line_prefix, c_meta, c_reset);
 }
 
 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
@@ -782,6 +788,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	struct userdiff_driver *userdiff;
 	struct userdiff_driver *textconv = NULL;
 	int is_binary;
+	const char *line_prefix = diff_line_prefix(opt);
 
 	context = opt->context;
 	userdiff = userdiff_find_by_path(elem->path);
@@ -901,7 +908,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	}
 	if (is_binary) {
 		show_combined_header(elem, num_parent, dense, rev,
-				     mode_differs, 0);
+				     line_prefix, mode_differs, 0);
 		printf("Binary files differ\n");
 		free(result);
 		return;
@@ -962,8 +969,8 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
 	if (show_hunks || mode_differs || working_tree_file) {
 		show_combined_header(elem, num_parent, dense, rev,
-				     mode_differs, 1);
-		dump_sline(sline, cnt, num_parent,
+				     line_prefix, mode_differs, 1);
+		dump_sline(sline, line_prefix, cnt, num_parent,
 			   opt->use_color, result_deleted);
 	}
 	free(result);
@@ -990,6 +997,7 @@ static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct re
 	int i, offset;
 	const char *prefix;
 	int line_termination, inter_name_termination;
+	const char *line_prefix = diff_line_prefix(opt);
 
 	line_termination = opt->line_termination;
 	inter_name_termination = '\t';
@@ -1000,6 +1008,7 @@ static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct re
 		show_log(rev);
 
 	if (opt->output_format & DIFF_FORMAT_RAW) {
+		printf("%s", line_prefix);
 		offset = strlen(COLONS) - num_parent;
 		if (offset < 0)
 			offset = 0;
@@ -1040,6 +1049,7 @@ void show_combined_diff(struct combine_diff_path *p,
 		       struct rev_info *rev)
 {
 	struct diff_options *opt = &rev->diffopt;
+
 	if (!p->len)
 		return;
 	if (opt->output_format & (DIFF_FORMAT_RAW |
@@ -1150,8 +1160,10 @@ void diff_tree_combined(const unsigned char *sha1,
 
 		if (show_log_first && i == 0) {
 			show_log(rev);
+
 			if (rev->verbose_header && opt->output_format)
-				putchar(opt->line_termination);
+				printf("%s%c", diff_line_prefix(opt),
+				       opt->line_termination);
 		}
 		diff_flush(&diffopts);
 	}
@@ -1179,7 +1191,8 @@ void diff_tree_combined(const unsigned char *sha1,
 
 		if (opt->output_format & DIFF_FORMAT_PATCH) {
 			if (needsep)
-				putchar(opt->line_termination);
+				printf("%s%c", diff_line_prefix(opt),
+				       opt->line_termination);
 			for (p = paths; p; p = p->next) {
 				if (p->len)
 					show_patch_diff(p, num_parent, dense,
-- 
1.8.1.2

Re: [PATCH 0/6] Improve "git log --graph" output of merges

[Junio C Hamano]

John Keeping <john@keeping.me.uk> writes:

> This series changes a couple of places that do not currently indent
> their output when being shown with a graph.
>
> The first patch was already posted [1] and addresses the output of "git
> log --graph -c -p".  Patch 2 is an independent fix I noticed while
> working on the later patches.
>
> Patches 3-5 introduce a helper function and change existing sites using
> diff_options->output_prefix to use it, resulting in a net reduction by
> about 60 lines.  There is no functional change here.
>
> The final patch uses the helper introduced in patch 4 to make combined
> diffs should the output prefix before each line.  This affects the
> output of "git log --graph --cc [-p|--raw]".
>
> [1] http://article.gmane.org/gmane.comp.version-control.git/215630

Overall direction looks sensible.

It is a bit scary that we are doing the the fifth one now, as
opposed to catching this repetitiveness during the initial review of
patch series that added the graph code to the diff codepath.

Thanks.

> John Keeping (6):
>   graph: output padding for merge subsequent parents
>   diff: write prefix to the correct file
>   diff.c: make constant string arguments const
>   diff: add diff_line_prefix function
>   diff.c: use diff_line_prefix() where applicable
>   combine-diff.c: teach combined diffs about line prefix
>
>  combine-diff.c |  47 +++++++++++++--------
>  diff.c         | 131 +++++++++++++++------------------------------------------
>  diff.h         |   3 ++
>  graph.c        |  10 +++++
>  4 files changed, 77 insertions(+), 114 deletions(-)

Re: [PATCH 1/6] graph: output padding for merge subsequent parents

[John Keeping]

[Moved from the thread where this was initially posted to reply to the
series.]

Matthieu Moy <Matthieu.Moy@grenoble-inp.fr> wrote:
> This works, but if we know we're not going to enter the while loop, it
> seams even easier to do this:
> 
> --- a/graph.c
> +++ b/graph.c
> @@ -1227,7 +1227,17 @@ void graph_show_commit(struct git_graph *graph)
>         if (!graph)
>                 return;
>  
> -       while (!shown_commit_line && !graph_is_commit_finished(graph)) {
> +       /*
> +        * When showing a diff of a merge against each of its parents, we
> +        * are called once for each parent without graph_update having been
> +        * called.  In this case, simply output a single padding line.
> +        */
> +       if (graph_is_commit_finished(graph)) {
> +               graph_show_padding(graph);
> +               return;
> +       }
> +
> +       while (!shown_commit_line) {

This looks good to me.  I'll amend locally and re-send in a few days
after giving others a chance to comment.


John