1 files changed, 418 insertions, 123 deletions

diff --git a/log-tree.c b/log-tree.c
index 6ce239d8f9..b46ed3baef 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -1,36 +1,192 @@
 #include "cache.h"
 #include "diff.h"
 #include "commit.h"
+#include "tag.h"
+#include "graph.h"
 #include "log-tree.h"
 #include "reflog-walk.h"
+#include "refs.h"
+#include "string-list.h"
+#include "color.h"
+
+struct decoration name_decoration = { "object names" };
+
+enum decoration_type {
+	DECORATION_NONE = 0,
+	DECORATION_REF_LOCAL,
+	DECORATION_REF_REMOTE,
+	DECORATION_REF_TAG,
+	DECORATION_REF_STASH,
+	DECORATION_REF_HEAD,
+};
+
+static char decoration_colors[][COLOR_MAXLEN] = {
+	GIT_COLOR_RESET,
+	GIT_COLOR_BOLD_GREEN,	/* REF_LOCAL */
+	GIT_COLOR_BOLD_RED,	/* REF_REMOTE */
+	GIT_COLOR_BOLD_YELLOW,	/* REF_TAG */
+	GIT_COLOR_BOLD_MAGENTA,	/* REF_STASH */
+	GIT_COLOR_BOLD_CYAN,	/* REF_HEAD */
+};
+
+static const char *decorate_get_color(int decorate_use_color, enum decoration_type ix)
+{
+	if (decorate_use_color)
+		return decoration_colors[ix];
+	return "";
+}
+
+static int parse_decorate_color_slot(const char *slot)
+{
+	/*
+	 * We're comparing with 'ignore-case' on
+	 * (because config.c sets them all tolower),
+	 * but let's match the letters in the literal
+	 * string values here with how they are
+	 * documented in Documentation/config.txt, for
+	 * consistency.
+	 *
+	 * We love being consistent, don't we?
+	 */
+	if (!strcasecmp(slot, "branch"))
+		return DECORATION_REF_LOCAL;
+	if (!strcasecmp(slot, "remoteBranch"))
+		return DECORATION_REF_REMOTE;
+	if (!strcasecmp(slot, "tag"))
+		return DECORATION_REF_TAG;
+	if (!strcasecmp(slot, "stash"))
+		return DECORATION_REF_STASH;
+	if (!strcasecmp(slot, "HEAD"))
+		return DECORATION_REF_HEAD;
+	return -1;
+}
+
+int parse_decorate_color_config(const char *var, const int ofs, const char *value)
+{
+	int slot = parse_decorate_color_slot(var + ofs);
+	if (slot < 0)
+		return 0;
+	if (!value)
+		return config_error_nonbool(var);
+	color_parse(value, var, decoration_colors[slot]);
+	return 0;
+}
+
+/*
+ * log-tree.c uses DIFF_OPT_TST for determining whether to use color
+ * for showing the commit sha1, use the same check for --decorate
+ */
+#define decorate_get_color_opt(o, ix) \
+	decorate_get_color(DIFF_OPT_TST((o), COLOR_DIFF), ix)
+
+static void add_name_decoration(enum decoration_type type, const char *name, struct object *obj)
+{
+	int nlen = strlen(name);
+	struct name_decoration *res = xmalloc(sizeof(struct name_decoration) + nlen);
+	memcpy(res->name, name, nlen + 1);
+	res->type = type;
+	res->next = add_decoration(&name_decoration, obj, res);
+}
+
+static int add_ref_decoration(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
+{
+	struct object *obj = parse_object(sha1);
+	enum decoration_type type = DECORATION_NONE;
+	if (!obj)
+		return 0;
+
+	if (!prefixcmp(refname, "refs/heads"))
+		type = DECORATION_REF_LOCAL;
+	else if (!prefixcmp(refname, "refs/remotes"))
+		type = DECORATION_REF_REMOTE;
+	else if (!prefixcmp(refname, "refs/tags"))
+		type = DECORATION_REF_TAG;
+	else if (!prefixcmp(refname, "refs/stash"))
+		type = DECORATION_REF_STASH;
+	else if (!prefixcmp(refname, "HEAD"))
+		type = DECORATION_REF_HEAD;
+
+	if (!cb_data || *(int *)cb_data == DECORATE_SHORT_REFS)
+		refname = prettify_refname(refname);
+	add_name_decoration(type, refname, obj);
+	while (obj->type == OBJ_TAG) {
+		obj = ((struct tag *)obj)->tagged;
+		if (!obj)
+			break;
+		add_name_decoration(DECORATION_REF_TAG, refname, obj);
+	}
+	return 0;
+}
+
+void load_ref_decorations(int flags)
+{
+	static int loaded;
+	if (!loaded) {
+		loaded = 1;
+		for_each_ref(add_ref_decoration, &flags);
+		head_ref(add_ref_decoration, &flags);
+	}
+}
 
 static void show_parents(struct commit *commit, int abbrev)
 {
 	struct commit_list *p;
 	for (p = commit->parents; p ; p = p->next) {
 		struct commit *parent = p->item;
-		printf(" %s", diff_unique_abbrev(parent->object.sha1, abbrev));
+		printf(" %s", find_unique_abbrev(parent->object.sha1, abbrev));
 	}
 }
 
+void show_decorations(struct rev_info *opt, struct commit *commit)
+{
+	const char *prefix;
+	struct name_decoration *decoration;
+	const char *color_commit =
+		diff_get_color_opt(&opt->diffopt, DIFF_COMMIT);
+	const char *color_reset =
+		decorate_get_color_opt(&opt->diffopt, DECORATION_NONE);
+
+	if (opt->show_source && commit->util)
+		printf("\t%s", (char *) commit->util);
+	if (!opt->show_decorations)
+		return;
+	decoration = lookup_decoration(&name_decoration, &commit->object);
+	if (!decoration)
+		return;
+	prefix = " (";
+	while (decoration) {
+		printf("%s", prefix);
+		fputs(decorate_get_color_opt(&opt->diffopt, decoration->type),
+		      stdout);
+		if (decoration->type == DECORATION_REF_TAG)
+			fputs("tag: ", stdout);
+		printf("%s", decoration->name);
+		fputs(color_reset, stdout);
+		fputs(color_commit, stdout);
+		prefix = ", ";
+		decoration = decoration->next;
+	}
+	putchar(')');
+}
+
 /*
  * Search for "^[-A-Za-z]+: [^@]+@" pattern. It usually matches
  * Signed-off-by: and Acked-by: lines.
  */
 static int detect_any_signoff(char *letter, int size)
 {
-	char ch, *cp;
+	char *cp;
 	int seen_colon = 0;
 	int seen_at = 0;
 	int seen_name = 0;
 	int seen_head = 0;
 
 	cp = letter + size;
-	while (letter <= --cp && (ch = *cp) == '\n')
+	while (letter <= --cp && *cp == '\n')
 		continue;
 
 	while (letter <= cp) {
-		ch = *cp--;
+		char ch = *cp--;
 		if (ch == '\n')
 			break;
 
@@ -60,16 +216,14 @@ static int detect_any_signoff(char *letter, int size)
 	return seen_head && seen_name;
 }
 
-static int append_signoff(char *buf, int buf_sz, int at, const char *signoff)
+static void append_signoff(struct strbuf *sb, const char *signoff)
 {
 	static const char signed_off_by[] = "Signed-off-by: ";
-	int signoff_len = strlen(signoff);
+	size_t signoff_len = strlen(signoff);
 	int has_signoff = 0;
-	char *cp = buf;
+	char *cp;
 
-	/* Do we have enough space to add it? */
-	if (buf_sz - at <= strlen(signed_off_by) + signoff_len + 3)
-		return at;
+	cp = sb->buf;
 
 	/* First see if we already have the sign-off by the signer */
 	while ((cp = strstr(cp, signed_off_by))) {
@@ -77,29 +231,25 @@ static int append_signoff(char *buf, int buf_sz, int at, const char *signoff)
 		has_signoff = 1;
 
 		cp += strlen(signed_off_by);
-		if (cp + signoff_len >= buf + at)
+		if (cp + signoff_len >= sb->buf + sb->len)
 			break;
 		if (strncmp(cp, signoff, signoff_len))
 			continue;
 		if (!isspace(cp[signoff_len]))
 			continue;
 		/* we already have him */
-		return at;
+		return;
 	}
 
 	if (!has_signoff)
-		has_signoff = detect_any_signoff(buf, at);
+		has_signoff = detect_any_signoff(sb->buf, sb->len);
 
 	if (!has_signoff)
-		buf[at++] = '\n';
-
-	strcpy(buf + at, signed_off_by);
-	at += strlen(signed_off_by);
-	strcpy(buf + at, signoff);
-	at += signoff_len;
-	buf[at++] = '\n';
-	buf[at] = 0;
-	return at;
+		strbuf_addch(sb, '\n');
+
+	strbuf_addstr(sb, signed_off_by);
+	strbuf_add(sb, signoff, signoff_len);
+	strbuf_addch(sb, '\n');
 }
 
 static unsigned int digits_in_number(unsigned int number)
@@ -112,151 +262,278 @@ static unsigned int digits_in_number(unsigned int number)
 	return result;
 }
 
-void show_log(struct rev_info *opt, const char *sep)
+void get_patch_filename(struct commit *commit, int nr, const char *suffix,
+			struct strbuf *buf)
+{
+	int suffix_len = strlen(suffix) + 1;
+	int start_len = buf->len;
+
+	strbuf_addf(buf, commit ? "%04d-" : "%d", nr);
+	if (commit) {
+		int max_len = start_len + FORMAT_PATCH_NAME_MAX - suffix_len;
+		struct pretty_print_context ctx = {0};
+		ctx.date_mode = DATE_NORMAL;
+
+		format_commit_message(commit, "%f", buf, &ctx);
+		if (max_len < buf->len)
+			strbuf_setlen(buf, max_len);
+		strbuf_addstr(buf, suffix);
+	}
+}
+
+void log_write_email_headers(struct rev_info *opt, struct commit *commit,
+			     const char **subject_p,
+			     const char **extra_headers_p,
+			     int *need_8bit_cte_p)
+{
+	const char *subject = NULL;
+	const char *extra_headers = opt->extra_headers;
+	const char *name = sha1_to_hex(commit->object.sha1);
+
+	*need_8bit_cte_p = 0; /* unknown */
+	if (opt->total > 0) {
+		static char buffer[64];
+		snprintf(buffer, sizeof(buffer),
+			 "Subject: [%s %0*d/%d] ",
+			 opt->subject_prefix,
+			 digits_in_number(opt->total),
+			 opt->nr, opt->total);
+		subject = buffer;
+	} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
+		static char buffer[256];
+		snprintf(buffer, sizeof(buffer),
+			 "Subject: [%s] ",
+			 opt->subject_prefix);
+		subject = buffer;
+	} else {
+		subject = "Subject: ";
+	}
+
+	printf("From %s Mon Sep 17 00:00:00 2001\n", name);
+	graph_show_oneline(opt->graph);
+	if (opt->message_id) {
+		printf("Message-Id: <%s>\n", opt->message_id);
+		graph_show_oneline(opt->graph);
+	}
+	if (opt->ref_message_ids && opt->ref_message_ids->nr > 0) {
+		int i, n;
+		n = opt->ref_message_ids->nr;
+		printf("In-Reply-To: <%s>\n", opt->ref_message_ids->items[n-1].string);
+		for (i = 0; i < n; i++)
+			printf("%s<%s>\n", (i > 0 ? "\t" : "References: "),
+			       opt->ref_message_ids->items[i].string);
+		graph_show_oneline(opt->graph);
+	}
+	if (opt->mime_boundary) {
+		static char subject_buffer[1024];
+		static char buffer[1024];
+		struct strbuf filename =  STRBUF_INIT;
+		*need_8bit_cte_p = -1; /* NEVER */
+		snprintf(subject_buffer, sizeof(subject_buffer) - 1,
+			 "%s"
+			 "MIME-Version: 1.0\n"
+			 "Content-Type: multipart/mixed;"
+			 " boundary=\"%s%s\"\n"
+			 "\n"
+			 "This is a multi-part message in MIME "
+			 "format.\n"
+			 "--%s%s\n"
+			 "Content-Type: text/plain; "
+			 "charset=UTF-8; format=fixed\n"
+			 "Content-Transfer-Encoding: 8bit\n\n",
+			 extra_headers ? extra_headers : "",
+			 mime_boundary_leader, opt->mime_boundary,
+			 mime_boundary_leader, opt->mime_boundary);
+		extra_headers = subject_buffer;
+
+		get_patch_filename(opt->numbered_files ? NULL : commit, opt->nr,
+				    opt->patch_suffix, &filename);
+		snprintf(buffer, sizeof(buffer) - 1,
+			 "\n--%s%s\n"
+			 "Content-Type: text/x-patch;"
+			 " name=\"%s\"\n"
+			 "Content-Transfer-Encoding: 8bit\n"
+			 "Content-Disposition: %s;"
+			 " filename=\"%s\"\n\n",
+			 mime_boundary_leader, opt->mime_boundary,
+			 filename.buf,
+			 opt->no_inline ? "attachment" : "inline",
+			 filename.buf);
+		opt->diffopt.stat_sep = buffer;
+		strbuf_release(&filename);
+	}
+	*subject_p = subject;
+	*extra_headers_p = extra_headers;
+}
+
+void show_log(struct rev_info *opt)
 {
-	static char this_header[16384];
+	struct strbuf msgbuf = STRBUF_INIT;
 	struct log_info *log = opt->loginfo;
 	struct commit *commit = log->commit, *parent = log->parent;
-	int abbrev = opt->diffopt.abbrev;
 	int abbrev_commit = opt->abbrev_commit ? opt->abbrev : 40;
-	const char *extra;
-	int len;
-	const char *subject = NULL, *extra_headers = opt->extra_headers;
+	const char *extra_headers = opt->extra_headers;
+	struct pretty_print_context ctx = {0};
 
 	opt->loginfo = NULL;
+	ctx.show_notes = opt->show_notes;
 	if (!opt->verbose_header) {
-		if (opt->left_right) {
+		graph_show_commit(opt->graph);
+
+		if (!opt->graph) {
 			if (commit->object.flags & BOUNDARY)
 				putchar('-');
-			else if (commit->object.flags & SYMMETRIC_LEFT)
-				putchar('<');
-			else
-				putchar('>');
+			else if (commit->object.flags & UNINTERESTING)
+				putchar('^');
+			else if (opt->left_right) {
+				if (commit->object.flags & SYMMETRIC_LEFT)
+					putchar('<');
+				else
+					putchar('>');
+			}
 		}
-		fputs(diff_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
-		if (opt->parents)
+		fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit), stdout);
+		if (opt->print_parents)
 			show_parents(commit, abbrev_commit);
+		show_decorations(opt, commit);
+		if (opt->graph && !graph_is_commit_finished(opt->graph)) {
+			putchar('\n');
+			graph_show_remainder(opt->graph);
+		}
 		putchar(opt->diffopt.line_termination);
 		return;
 	}
 
 	/*
-	 * The "oneline" format has several special cases:
-	 *  - The pretty-printed commit lacks a newline at the end
-	 *    of the buffer, but we do want to make sure that we
-	 *    have a newline there. If the separator isn't already
-	 *    a newline, add an extra one.
-	 *  - unlike other log messages, the one-line format does
-	 *    not have an empty line between entries.
+	 * If use_terminator is set, we already handled any record termination
+	 * at the end of the last record.
+	 * Otherwise, add a diffopt.line_termination character before all
+	 * entries but the first.  (IOW, as a separator between entries)
 	 */
-	extra = "";
-	if (*sep != '\n' && opt->commit_format == CMIT_FMT_ONELINE)
-		extra = "\n";
-	if (opt->shown_one && opt->commit_format != CMIT_FMT_ONELINE)
+	if (opt->shown_one && !opt->use_terminator) {
+		/*
+		 * If entries are separated by a newline, the output
+		 * should look human-readable.  If the last entry ended
+		 * with a newline, print the graph output before this
+		 * newline.  Otherwise it will end up as a completely blank
+		 * line and will look like a gap in the graph.
+		 *
+		 * If the entry separator is not a newline, the output is
+		 * primarily intended for programmatic consumption, and we
+		 * never want the extra graph output before the entry
+		 * separator.
+		 */
+		if (opt->diffopt.line_termination == '\n' &&
+		    !opt->missing_newline)
+			graph_show_padding(opt->graph);
 		putchar(opt->diffopt.line_termination);
+	}
 	opt->shown_one = 1;
 
 	/*
+	 * If the history graph was requested,
+	 * print the graph, up to this commit's line
+	 */
+	graph_show_commit(opt->graph);
+
+	/*
 	 * Print header line of header..
 	 */
 
 	if (opt->commit_format == CMIT_FMT_EMAIL) {
-		char *sha1 = sha1_to_hex(commit->object.sha1);
-		if (opt->total > 0) {
-			static char buffer[64];
-			snprintf(buffer, sizeof(buffer),
-					"Subject: [PATCH %0*d/%d] ",
-					digits_in_number(opt->total),
-					opt->nr, opt->total);
-			subject = buffer;
-		} else if (opt->total == 0)
-			subject = "Subject: [PATCH] ";
-		else
-			subject = "Subject: ";
-
-		printf("From %s Mon Sep 17 00:00:00 2001\n", sha1);
-		if (opt->message_id)
-			printf("Message-Id: <%s>\n", opt->message_id);
-		if (opt->ref_message_id)
-			printf("In-Reply-To: <%s>\nReferences: <%s>\n",
-			       opt->ref_message_id, opt->ref_message_id);
-		if (opt->mime_boundary) {
-			static char subject_buffer[1024];
-			static char buffer[1024];
-			snprintf(subject_buffer, sizeof(subject_buffer) - 1,
-				 "%s"
-				 "MIME-Version: 1.0\n"
-				 "Content-Type: multipart/mixed;\n"
-				 " boundary=\"%s%s\"\n"
-				 "\n"
-				 "This is a multi-part message in MIME "
-				 "format.\n"
-				 "--%s%s\n"
-				 "Content-Type: text/plain; "
-				 "charset=UTF-8; format=fixed\n"
-				 "Content-Transfer-Encoding: 8bit\n\n",
-				 extra_headers ? extra_headers : "",
-				 mime_boundary_leader, opt->mime_boundary,
-				 mime_boundary_leader, opt->mime_boundary);
-			extra_headers = subject_buffer;
-
-			snprintf(buffer, sizeof(buffer) - 1,
-				 "--%s%s\n"
-				 "Content-Type: text/x-patch;\n"
-				 " name=\"%s.diff\"\n"
-				 "Content-Transfer-Encoding: 8bit\n"
-				 "Content-Disposition: inline;\n"
-				 " filename=\"%s.diff\"\n\n",
-				 mime_boundary_leader, opt->mime_boundary,
-				 sha1, sha1);
-			opt->diffopt.stat_sep = buffer;
-		}
+		log_write_email_headers(opt, commit, &ctx.subject, &extra_headers,
+					&ctx.need_8bit_cte);
 	} else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
-		fputs(diff_get_color(opt->diffopt.color_diff, DIFF_COMMIT),
-		      stdout);
+		fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), stdout);
 		if (opt->commit_format != CMIT_FMT_ONELINE)
 			fputs("commit ", stdout);
-		if (opt->left_right) {
+
+		if (!opt->graph) {
 			if (commit->object.flags & BOUNDARY)
 				putchar('-');
-			else if (commit->object.flags & SYMMETRIC_LEFT)
-				putchar('<');
-			else
-				putchar('>');
+			else if (commit->object.flags & UNINTERESTING)
+				putchar('^');
+			else if (opt->left_right) {
+				if (commit->object.flags & SYMMETRIC_LEFT)
+					putchar('<');
+				else
+					putchar('>');
+			}
 		}
-		fputs(diff_unique_abbrev(commit->object.sha1, abbrev_commit),
+		fputs(find_unique_abbrev(commit->object.sha1, abbrev_commit),
 		      stdout);
-		if (opt->parents)
+		if (opt->print_parents)
 			show_parents(commit, abbrev_commit);
 		if (parent)
 			printf(" (from %s)",
-			       diff_unique_abbrev(parent->object.sha1,
+			       find_unique_abbrev(parent->object.sha1,
 						  abbrev_commit));
-		printf("%s",
-		       diff_get_color(opt->diffopt.color_diff, DIFF_RESET));
-		putchar(opt->commit_format == CMIT_FMT_ONELINE ? ' ' : '\n');
+		show_decorations(opt, commit);
+		printf("%s", diff_get_color_opt(&opt->diffopt, DIFF_RESET));
+		if (opt->commit_format == CMIT_FMT_ONELINE) {
+			putchar(' ');
+		} else {
+			putchar('\n');
+			graph_show_oneline(opt->graph);
+		}
 		if (opt->reflog_info) {
+			/*
+			 * setup_revisions() ensures that opt->reflog_info
+			 * and opt->graph cannot both be set,
+			 * so we don't need to worry about printing the
+			 * graph info here.
+			 */
 			show_reflog_message(opt->reflog_info,
 				    opt->commit_format == CMIT_FMT_ONELINE,
-				    opt->relative_date);
-			if (opt->commit_format == CMIT_FMT_ONELINE) {
-				printf("%s", sep);
+				    opt->date_mode_explicit ?
+					opt->date_mode :
+					DATE_NORMAL);
+			if (opt->commit_format == CMIT_FMT_ONELINE)
 				return;
-			}
 		}
 	}
 
+	if (!commit->buffer)
+		return;
+
 	/*
 	 * And then the pretty-printed message itself
 	 */
-	len = pretty_print_commit(opt->commit_format, commit, ~0u, this_header,
-				  sizeof(this_header), abbrev, subject,
-				  extra_headers, opt->relative_date);
+	if (ctx.need_8bit_cte >= 0)
+		ctx.need_8bit_cte = has_non_ascii(opt->add_signoff);
+	ctx.date_mode = opt->date_mode;
+	ctx.abbrev = opt->diffopt.abbrev;
+	ctx.after_subject = extra_headers;
+	ctx.reflog_info = opt->reflog_info;
+	pretty_print_commit(opt->commit_format, commit, &msgbuf, &ctx);
 
 	if (opt->add_signoff)
-		len = append_signoff(this_header, sizeof(this_header), len,
-				     opt->add_signoff);
-	printf("%s%s%s", this_header, extra, sep);
+		append_signoff(&msgbuf, opt->add_signoff);
+	if (opt->show_log_size) {
+		printf("log size %i\n", (int)msgbuf.len);
+		graph_show_oneline(opt->graph);
+	}
+
+	/*
+	 * Set opt->missing_newline if msgbuf doesn't
+	 * end in a newline (including if it is empty)
+	 */
+	if (!msgbuf.len || msgbuf.buf[msgbuf.len - 1] != '\n')
+		opt->missing_newline = 1;
+	else
+		opt->missing_newline = 0;
+
+	if (opt->graph)
+		graph_show_commit_msg(opt->graph, &msgbuf);
+	else
+		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
+	if (opt->use_terminator) {
+		if (!opt->missing_newline)
+			graph_show_padding(opt->graph);
+		putchar('\n');
+	}
+
+	strbuf_release(&msgbuf);
 }
 
 int log_tree_diff_flush(struct rev_info *opt)
@@ -277,12 +554,19 @@ int log_tree_diff_flush(struct rev_info *opt)
 		 * an extra newline between the end of log and the
 		 * output for readability.
 		 */
-		show_log(opt, opt->diffopt.msg_sep);
-		if (opt->verbose_header &&
+		show_log(opt);
+		if ((opt->diffopt.output_format & ~DIFF_FORMAT_NO_OUTPUT) &&
+		    opt->verbose_header &&
 		    opt->commit_format != CMIT_FMT_ONELINE) {
 			int pch = DIFF_FORMAT_DIFFSTAT | DIFF_FORMAT_PATCH;
 			if ((pch & opt->diffopt.output_format) == pch)
 				printf("---");
+			if (opt->diffopt.output_prefix) {
+				struct strbuf *msg = NULL;
+				msg = opt->diffopt.output_prefix(&opt->diffopt,
+					opt->diffopt.output_prefix_data);
+				fwrite(msg->buf, msg->len, 1, stdout);
+			}
 			putchar('\n');
 		}
 	}
@@ -309,7 +593,7 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
 	struct commit_list *parents;
 	unsigned const char *sha1 = commit->object.sha1;
 
-	if (!opt->diff)
+	if (!opt->diff && !DIFF_OPT_TST(&opt->diffopt, EXIT_WITH_STATUS))
 		return 0;
 
 	/* Root commit? */
@@ -328,6 +612,16 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
 			return 0;
 		else if (opt->combine_merges)
 			return do_diff_combined(opt, commit);
+		else if (opt->first_parent_only) {
+			/*
+			 * Generate merge log entry only for the first
+			 * parent, showing summary diff of the others
+			 * we merged _in_.
+			 */
+			diff_tree_sha1(parents->item->object.sha1, sha1, "", &opt->diffopt);
+			log_tree_diff_flush(opt);
+			return !opt->loginfo;
+		}
 
 		/* If we show individual diffs, show the parent info */
 		log->parent = parents->item;
@@ -364,9 +658,10 @@ int log_tree_commit(struct rev_info *opt, struct commit *commit)
 	shown = log_tree_diff(opt, commit, &log);
 	if (!shown && opt->loginfo && opt->always_show_header) {
 		log.parent = NULL;
-		show_log(opt, "");
+		show_log(opt);
 		shown = 1;
 	}
 	opt->loginfo = NULL;
+	maybe_flush_or_die(stdout, "stdout");
 	return shown;
 }