Merge branch 'js/log-to-diffopt-file'

The commands in the "log/diff" family have had an FILE* pointer in the
data structure they pass around for a long time, but some codepaths
used to always write to the standard output.  As a preparatory step
to make "git format-patch" available to the internal callers, these
codepaths have been updated to consistently write into that FILE*
instead.

* js/log-to-diffopt-file:
  mingw: fix the shortlog --output=<file> test
  diff: do not color output when --color=auto and --output=<file> is given
  t4211: ensure that log respects --output=<file>
  shortlog: respect the --output=<file> setting
  format-patch: use stdout directly
  format-patch: avoid freopen()
  format-patch: explicitly switch off color when writing to files
  shortlog: support outputting to streams other than stdout
  graph: respect the diffopt.file setting
  line-log: respect diffopt's configured output file stream
  log-tree: respect diffopt's configured output file stream
  log: prepare log/log-tree to reuse the diffopt.close_file attribute

9 files changed, 144 insertions, 107 deletions

diff --git a/builtin/log.c b/builtin/log.c
index 0b6f7392b..fd1652f52 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -238,16 +238,17 @@ static void show_early_header(struct rev_info *rev, const char *stage, int nr)
 		if (rev->commit_format != CMIT_FMT_ONELINE)
 			putchar(rev->diffopt.line_termination);
 	}
-	printf(_("Final output: %d %s\n"), nr, stage);
+	fprintf(rev->diffopt.file, _("Final output: %d %s\n"), nr, stage);
 }
 
 static struct itimerval early_output_timer;
 
 static void log_show_early(struct rev_info *revs, struct commit_list *list)
 {
-	int i = revs->early_output;
+	int i = revs->early_output, close_file = revs->diffopt.close_file;
 	int show_header = 1;
 
+	revs->diffopt.close_file = 0;
 	sort_in_topological_order(&list, revs->sort_order);
 	while (list && i) {
 		struct commit *commit = list->item;
@@ -264,14 +265,19 @@ static void log_show_early(struct rev_info *revs, struct commit_list *list)
 		case commit_ignore:
 			break;
 		case commit_error:
+			if (close_file)
+				fclose(revs->diffopt.file);
 			return;
 		}
 		list = list->next;
 	}
 
 	/* Did we already get enough commits for the early output? */
-	if (!i)
+	if (!i) {
+		if (close_file)
+			fclose(revs->diffopt.file);
 		return;
+	}
 
 	/*
 	 * ..if no, then repeat it twice a second until we
@@ -333,7 +339,7 @@ static int cmd_log_walk(struct rev_info *rev)
 {
 	struct commit *commit;
 	int saved_nrl = 0;
-	int saved_dcctc = 0;
+	int saved_dcctc = 0, close_file = rev->diffopt.close_file;
 
 	if (rev->early_output)
 		setup_early_output(rev);
@@ -349,6 +355,7 @@ static int cmd_log_walk(struct rev_info *rev)
 	 * and HAS_CHANGES being accumulated in rev->diffopt, so be careful to
 	 * retain that state information if replacing rev->diffopt in this loop
 	 */
+	rev->diffopt.close_file = 0;
 	while ((commit = get_revision(rev)) != NULL) {
 		if (!log_tree_commit(rev, commit) && rev->max_count >= 0)
 			/*
@@ -369,6 +376,8 @@ static int cmd_log_walk(struct rev_info *rev)
 	}
 	rev->diffopt.degraded_cc_to_c = saved_dcctc;
 	rev->diffopt.needed_rename_limit = saved_nrl;
+	if (close_file)
+		fclose(rev->diffopt.file);
 
 	if (rev->diffopt.output_format & DIFF_FORMAT_CHECKDIFF &&
 	    DIFF_OPT_TST(&rev->diffopt, CHECK_FAILED)) {
@@ -451,7 +460,7 @@ static void show_tagger(char *buf, int len, struct rev_info *rev)
 	pp.fmt = rev->commit_format;
 	pp.date_mode = rev->date_mode;
 	pp_user_info(&pp, "Tagger", &out, buf, get_log_output_encoding());
-	printf("%s", out.buf);
+	fprintf(rev->diffopt.file, "%s", out.buf);
 	strbuf_release(&out);
 }
 
@@ -462,7 +471,7 @@ static int show_blob_object(const unsigned char *sha1, struct rev_info *rev, con
 	char *buf;
 	unsigned long size;
 
-	fflush(stdout);
+	fflush(rev->diffopt.file);
 	if (!DIFF_OPT_TOUCHED(&rev->diffopt, ALLOW_TEXTCONV) ||
 	    !DIFF_OPT_TST(&rev->diffopt, ALLOW_TEXTCONV))
 		return stream_blob_to_fd(1, sha1, NULL, 0);
@@ -502,7 +511,7 @@ static int show_tag_object(const unsigned char *sha1, struct rev_info *rev)
 	}
 
 	if (offset < size)
-		fwrite(buf + offset, size - offset, 1, stdout);
+		fwrite(buf + offset, size - offset, 1, rev->diffopt.file);
 	free(buf);
 	return 0;
 }
@@ -511,7 +520,8 @@ static int show_tree_object(const unsigned char *sha1,
 		struct strbuf *base,
 		const char *pathname, unsigned mode, int stage, void *context)
 {
-	printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
+	FILE *file = context;
+	fprintf(file, "%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
 	return 0;
 }
 
@@ -571,7 +581,7 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 
 			if (rev.shown_one)
 				putchar('\n');
-			printf("%stag %s%s\n",
+			fprintf(rev.diffopt.file, "%stag %s%s\n",
 					diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 					t->tag,
 					diff_get_color_opt(&rev.diffopt, DIFF_RESET));
@@ -590,12 +600,12 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 		case OBJ_TREE:
 			if (rev.shown_one)
 				putchar('\n');
-			printf("%stree %s%s\n\n",
+			fprintf(rev.diffopt.file, "%stree %s%s\n\n",
 					diff_get_color_opt(&rev.diffopt, DIFF_COMMIT),
 					name,
 					diff_get_color_opt(&rev.diffopt, DIFF_RESET));
 			read_tree_recursive((struct tree *)o, "", 0, 0, &match_all,
-					show_tree_object, NULL);
+					show_tree_object, rev.diffopt.file);
 			rev.shown_one = 1;
 			break;
 		case OBJ_COMMIT:
@@ -801,11 +811,10 @@ static int git_format_config(const char *var, const char *value, void *cb)
 	return git_log_config(var, value, cb);
 }
 
-static FILE *realstdout = NULL;
 static const char *output_directory = NULL;
 static int outdir_offset;
 
-static int reopen_stdout(struct commit *commit, const char *subject,
+static int open_next_file(struct commit *commit, const char *subject,
 			 struct rev_info *rev, int quiet)
 {
 	struct strbuf filename = STRBUF_INIT;
@@ -827,9 +836,9 @@ static int reopen_stdout(struct commit *commit, const char *subject,
 		fmt_output_subject(&filename, subject, rev);
 
 	if (!quiet)
-		fprintf(realstdout, "%s\n", filename.buf + outdir_offset);
+		printf("%s\n", filename.buf + outdir_offset);
 
-	if (freopen(filename.buf, "w", stdout) == NULL)
+	if ((rev->diffopt.file = fopen(filename.buf, "w")) == NULL)
 		return error(_("Cannot open patch file %s"), filename.buf);
 
 	strbuf_release(&filename);
@@ -888,15 +897,15 @@ static void gen_message_id(struct rev_info *info, char *base)
 	info->message_id = strbuf_detach(&buf, NULL);
 }
 
-static void print_signature(void)
+static void print_signature(FILE *file)
 {
 	if (!signature || !*signature)
 		return;
 
-	printf("-- \n%s", signature);
+	fprintf(file, "-- \n%s", signature);
 	if (signature[strlen(signature)-1] != '\n')
-		putchar('\n');
-	putchar('\n');
+		putc('\n', file);
+	putc('\n', file);
 }
 
 static void add_branch_description(struct strbuf *buf, const char *branch_name)
@@ -965,7 +974,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 	committer = git_committer_info(0);
 
 	if (!use_stdout &&
-	    reopen_stdout(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
+	    open_next_file(NULL, rev->numbered_files ? NULL : "cover-letter", rev, quiet))
 		return;
 
 	log_write_email_headers(rev, head, &pp.subject, &pp.after_subject,
@@ -988,7 +997,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 	pp_title_line(&pp, &msg, &sb, encoding, need_8bit_cte);
 	pp_remainder(&pp, &msg, &sb, 0);
 	add_branch_description(&sb, branch_name);
-	printf("%s\n", sb.buf);
+	fprintf(rev->diffopt.file, "%s\n", sb.buf);
 
 	strbuf_release(&sb);
 
@@ -997,6 +1006,7 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 	log.wrap = 72;
 	log.in1 = 2;
 	log.in2 = 4;
+	log.file = rev->diffopt.file;
 	for (i = 0; i < nr; i++)
 		shortlog_add_commit(&log, list[i]);
 
@@ -1019,8 +1029,8 @@ static void make_cover_letter(struct rev_info *rev, int use_stdout,
 	diffcore_std(&opts);
 	diff_flush(&opts);
 
-	printf("\n");
-	print_signature();
+	fprintf(rev->diffopt.file, "\n");
+	print_signature(rev->diffopt.file);
 }
 
 static const char *clean_message_id(const char *msg_id)
@@ -1330,7 +1340,7 @@ static void prepare_bases(struct base_tree_info *bases,
 	}
 }
 
-static void print_bases(struct base_tree_info *bases)
+static void print_bases(struct base_tree_info *bases, FILE *file)
 {
 	int i;
 
@@ -1339,11 +1349,11 @@ static void print_bases(struct base_tree_info *bases)
 		return;
 
 	/* Show the base commit */
-	printf("base-commit: %s\n", oid_to_hex(&bases->base_commit));
+	fprintf(file, "base-commit: %s\n", oid_to_hex(&bases->base_commit));
 
 	/* Show the prerequisite patches */
 	for (i = bases->nr_patch_id - 1; i >= 0; i--)
-		printf("prerequisite-patch-id: %s\n", oid_to_hex(&bases->patch_id[i]));
+		fprintf(file, "prerequisite-patch-id: %s\n", oid_to_hex(&bases->patch_id[i]));
 
 	free(bases->patch_id);
 	bases->nr_patch_id = 0;
@@ -1575,6 +1585,8 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		setup_pager();
 
 	if (output_directory) {
+		if (rev.diffopt.use_color != GIT_COLOR_ALWAYS)
+			rev.diffopt.use_color = GIT_COLOR_NEVER;
 		if (use_stdout)
 			die(_("standard output, or directory, which one?"));
 		if (mkdir(output_directory, 0777) < 0 && errno != EEXIST)
@@ -1632,9 +1644,6 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		get_patch_ids(&rev, &ids);
 	}
 
-	if (!use_stdout)
-		realstdout = xfdopen(xdup(1), "w");
-
 	if (prepare_revision_walk(&rev))
 		die(_("revision walk setup failed"));
 	rev.boundary = 1;
@@ -1699,7 +1708,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			gen_message_id(&rev, "cover");
 		make_cover_letter(&rev, use_stdout,
 				  origin, nr, list, branch_name, quiet);
-		print_bases(&bases);
+		print_bases(&bases, rev.diffopt.file);
 		total++;
 		start_number--;
 	}
@@ -1745,7 +1754,7 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		}
 
 		if (!use_stdout &&
-		    reopen_stdout(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
+		    open_next_file(rev.numbered_files ? NULL : commit, NULL, &rev, quiet))
 			die(_("Failed to create output files"));
 		shown = log_tree_commit(&rev, commit);
 		free_commit_buffer(commit);
@@ -1760,15 +1769,15 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			rev.shown_one = 0;
 		if (shown) {
 			if (rev.mime_boundary)
-				printf("\n--%s%s--\n\n\n",
+				fprintf(rev.diffopt.file, "\n--%s%s--\n\n\n",
 				       mime_boundary_leader,
 				       rev.mime_boundary);
 			else
-				print_signature();
-			print_bases(&bases);
+				print_signature(rev.diffopt.file);
+			print_bases(&bases, rev.diffopt.file);
 		}
 		if (!use_stdout)
-			fclose(stdout);
+			fclose(rev.diffopt.file);
 	}
 	free(list);
 	free(branch_name);
@@ -1800,15 +1809,15 @@ static const char * const cherry_usage[] = {
 };
 
 static void print_commit(char sign, struct commit *commit, int verbose,
-			 int abbrev)
+			 int abbrev, FILE *file)
 {
 	if (!verbose) {
-		printf("%c %s\n", sign,
+		fprintf(file, "%c %s\n", sign,
 		       find_unique_abbrev(commit->object.oid.hash, abbrev));
 	} else {
 		struct strbuf buf = STRBUF_INIT;
 		pp_commit_easy(CMIT_FMT_ONELINE, commit, &buf);
-		printf("%c %s %s\n", sign,
+		fprintf(file, "%c %s %s\n", sign,
 		       find_unique_abbrev(commit->object.oid.hash, abbrev),
 		       buf.buf);
 		strbuf_release(&buf);
@@ -1889,7 +1898,7 @@ int cmd_cherry(int argc, const char **argv, const char *prefix)
 		commit = list->item;
 		if (has_commit_patch_id(commit, &ids))
 			sign = '-';
-		print_commit(sign, commit, verbose, abbrev);
+		print_commit(sign, commit, verbose, abbrev, revs.diffopt.file);
 		list = list->next;
 	}
 
diff --git a/builtin/shortlog.c b/builtin/shortlog.c
index f83984e8a..25fa8a6ae 100644
--- a/builtin/shortlog.c
+++ b/builtin/shortlog.c
@@ -276,6 +276,7 @@ parse_done:
 
 	log.user_format = rev.commit_format == CMIT_FMT_USERFORMAT;
 	log.abbrev = rev.abbrev;
+	log.file = rev.diffopt.file;
 
 	/* assume HEAD if from a tty */
 	if (!nongit && !rev.pending.nr && isatty(0))
@@ -289,6 +290,8 @@ parse_done:
 		get_from_rev(&rev, &log);
 
 	shortlog_output(&log);
+	if (log.file != stdout)
+		fclose(log.file);
 	return 0;
 }
 
@@ -310,22 +313,24 @@ void shortlog_output(struct shortlog *log)
 	for (i = 0; i < log->list.nr; i++) {
 		const struct string_list_item *item = &log->list.items[i];
 		if (log->summary) {
-			printf("%6d\t%s\n", (int)UTIL_TO_INT(item), item->string);
+			fprintf(log->file, "%6d\t%s\n",
+				(int)UTIL_TO_INT(item), item->string);
 		} else {
 			struct string_list *onelines = item->util;
-			printf("%s (%d):\n", item->string, onelines->nr);
+			fprintf(log->file, "%s (%d):\n",
+				item->string, onelines->nr);
 			for (j = onelines->nr - 1; j >= 0; j--) {
 				const char *msg = onelines->items[j].string;
 
 				if (log->wrap_lines) {
 					strbuf_reset(&sb);
 					add_wrapped_shortlog_msg(&sb, msg, log);
-					fwrite(sb.buf, sb.len, 1, stdout);
+					fwrite(sb.buf, sb.len, 1, log->file);
 				}
 				else
-					printf("      %s\n", msg);
+					fprintf(log->file, "      %s\n", msg);
 			}
-			putchar('\n');
+			putc('\n', log->file);
 			onelines->strdup_strings = 1;
 			string_list_clear(onelines, 0);
 			free(onelines);
diff --git a/diff.c b/diff.c
index fa78fc189..b66b9beab 100644
--- a/diff.c
+++ b/diff.c
@@ -3977,6 +3977,8 @@ int diff_opt_parse(struct diff_options *options,
 		if (!options->file)
 			die_errno("Could not open '%s'", path);
 		options->close_file = 1;
+		if (options->use_color != GIT_COLOR_ALWAYS)
+			options->use_color = GIT_COLOR_NEVER;
 		return argcount;
 	} else
 		return 0;
diff --git a/graph.c b/graph.c
index ad766faca..dd1720148 100644
--- a/graph.c
+++ b/graph.c
@@ -17,8 +17,8 @@
 static void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
 
 /*
- * Print a strbuf to stdout.  If the graph is non-NULL, all lines but the
- * first will be prefixed with the graph output.
+ * Print a strbuf.  If the graph is non-NULL, all lines but the first will be
+ * prefixed with the graph output.
  *
  * If the strbuf ends with a newline, the output will end after this
  * newline.  A new graph line will not be printed after the final newline.
@@ -1200,9 +1200,10 @@ void graph_show_commit(struct git_graph *graph)
 
 	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);
+		fwrite(msgbuf.buf, sizeof(char), msgbuf.len,
+			graph->revs->diffopt.file);
 		if (!shown_commit_line)
-			putchar('\n');
+			putc('\n', graph->revs->diffopt.file);
 		strbuf_setlen(&msgbuf, 0);
 	}
 
@@ -1217,7 +1218,7 @@ void graph_show_oneline(struct git_graph *graph)
 		return;
 
 	graph_next_line(graph, &msgbuf);
-	fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
+	fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file);
 	strbuf_release(&msgbuf);
 }
 
@@ -1229,7 +1230,7 @@ void graph_show_padding(struct git_graph *graph)
 		return;
 
 	graph_padding_line(graph, &msgbuf);
-	fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
+	fwrite(msgbuf.buf, sizeof(char), msgbuf.len, graph->revs->diffopt.file);
 	strbuf_release(&msgbuf);
 }
 
@@ -1246,12 +1247,13 @@ int graph_show_remainder(struct git_graph *graph)
 
 	for (;;) {
 		graph_next_line(graph, &msgbuf);
-		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
+		fwrite(msgbuf.buf, sizeof(char), msgbuf.len,
+			graph->revs->diffopt.file);
 		strbuf_setlen(&msgbuf, 0);
 		shown = 1;
 
 		if (!graph_is_commit_finished(graph))
-			putchar('\n');
+			putc('\n', graph->revs->diffopt.file);
 		else
 			break;
 	}
@@ -1266,7 +1268,8 @@ static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
 	char *p;
 
 	if (!graph) {
-		fwrite(sb->buf, sizeof(char), sb->len, stdout);
+		fwrite(sb->buf, sizeof(char), sb->len,
+			graph->revs->diffopt.file);
 		return;
 	}
 
@@ -1284,7 +1287,7 @@ static void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
 		} else {
 			len = (sb->buf + sb->len) - p;
 		}
-		fwrite(p, sizeof(char), len, stdout);
+		fwrite(p, sizeof(char), len, graph->revs->diffopt.file);
 		if (next_p && *next_p != '\0')
 			graph_show_oneline(graph);
 		p = next_p;
@@ -1304,7 +1307,8 @@ void graph_show_commit_msg(struct git_graph *graph,
 		 * CMIT_FMT_USERFORMAT are already missing a terminating
 		 * newline.  All of the other formats should have it.
 		 */
-		fwrite(sb->buf, sizeof(char), sb->len, stdout);
+		fwrite(sb->buf, sizeof(char), sb->len,
+			graph->revs->diffopt.file);
 		return;
 	}
 
@@ -1325,7 +1329,7 @@ void graph_show_commit_msg(struct git_graph *graph,
 		 * new line.
 		 */
 		if (!newline_terminated)
-			putchar('\n');
+			putc('\n', graph->revs->diffopt.file);
 
 		graph_show_remainder(graph);
 
@@ -1333,6 +1337,6 @@ void graph_show_commit_msg(struct git_graph *graph,
 		 * If sb ends with a newline, our output should too.
 		 */
 		if (newline_terminated)
-			putchar('\n');
+			putc('\n', graph->revs->diffopt.file);
 	}
 }
diff --git a/line-log.c b/line-log.c
index 1fbbe4f0a..a30c89a30 100644
--- a/line-log.c
+++ b/line-log.c
@@ -840,7 +840,7 @@ static char *get_nth_line(long line, unsigned long *ends, void *data)
 
 static void print_line(const char *prefix, char first,
 		       long line, unsigned long *ends, void *data,
-		       const char *color, const char *reset)
+		       const char *color, const char *reset, FILE *file)
 {
 	char *begin = get_nth_line(line, ends, data);
 	char *end = get_nth_line(line+1, ends, data);
@@ -851,14 +851,14 @@ static void print_line(const char *prefix, char first,
 		had_nl = 1;
 	}
 
-	fputs(prefix, stdout);
-	fputs(color, stdout);
-	putchar(first);
-	fwrite(begin, 1, end-begin, stdout);
-	fputs(reset, stdout);
-	putchar('\n');
+	fputs(prefix, file);
+	fputs(color, file);
+	putc(first, file);
+	fwrite(begin, 1, end-begin, file);
+	fputs(reset, file);
+	putc('\n', file);
 	if (!had_nl)
-		fputs("\\ No newline at end of file\n", stdout);
+		fputs("\\ No newline at end of file\n", file);
 }
 
 static char *output_prefix(struct diff_options *opt)
@@ -897,12 +897,12 @@ static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *rang
 		fill_line_ends(pair->one, &p_lines, &p_ends);
 	fill_line_ends(pair->two, &t_lines, &t_ends);
 
-	printf("%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
-	printf("%s%s--- %s%s%s\n", prefix, c_meta,
+	fprintf(opt->file, "%s%sdiff --git a/%s b/%s%s\n", prefix, c_meta, pair->one->path, pair->two->path, c_reset);
+	fprintf(opt->file, "%s%s--- %s%s%s\n", prefix, c_meta,
 	       pair->one->sha1_valid ? "a/" : "",
 	       pair->one->sha1_valid ? pair->one->path : "/dev/null",
 	       c_reset);
-	printf("%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
+	fprintf(opt->file, "%s%s+++ b/%s%s\n", prefix, c_meta, pair->two->path, c_reset);
 	for (i = 0; i < range->ranges.nr; i++) {
 		long p_start, p_end;
 		long t_start = range->ranges.ranges[i].start;
@@ -944,7 +944,7 @@ static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *rang
 		}
 
 		/* Now output a diff hunk for this range */
-		printf("%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
+		fprintf(opt->file, "%s%s@@ -%ld,%ld +%ld,%ld @@%s\n",
 		       prefix, c_frag,
 		       p_start+1, p_end-p_start, t_start+1, t_end-t_start,
 		       c_reset);
@@ -952,18 +952,18 @@ static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *rang
 			int k;
 			for (; t_cur < diff->target.ranges[j].start; t_cur++)
 				print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
-					   c_context, c_reset);
+					   c_context, c_reset, opt->file);
 			for (k = diff->parent.ranges[j].start; k < diff->parent.ranges[j].end; k++)
 				print_line(prefix, '-', k, p_ends, pair->one->data,
-					   c_old, c_reset);
+					   c_old, c_reset, opt->file);
 			for (; t_cur < diff->target.ranges[j].end && t_cur < t_end; t_cur++)
 				print_line(prefix, '+', t_cur, t_ends, pair->two->data,
-					   c_new, c_reset);
+					   c_new, c_reset, opt->file);
 			j++;
 		}
 		for (; t_cur < t_end; t_cur++)
 			print_line(prefix, ' ', t_cur, t_ends, pair->two->data,
-				   c_context, c_reset);
+				   c_context, c_reset, opt->file);
 	}
 
 	free(p_ends);
@@ -976,7 +976,7 @@ static void dump_diff_hacky_one(struct rev_info *rev, struct line_log_data *rang
  */
 static void dump_diff_hacky(struct rev_info *rev, struct line_log_data *range)
 {
-	puts(output_prefix(&rev->diffopt));
+	fprintf(rev->diffopt.file, "%s\n", output_prefix(&rev->diffopt));
 	while (range) {
 		dump_diff_hacky_one(rev, range);
 		range = range->next;
diff --git a/log-tree.c b/log-tree.c
index 9f678abc9..d0062e678 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -159,12 +159,12 @@ void load_ref_decorations(int flags)
 	}
 }
 
-static void show_parents(struct commit *commit, int abbrev)
+static void show_parents(struct commit *commit, int abbrev, FILE *file)
 {
 	struct commit_list *p;
 	for (p = commit->parents; p ; p = p->next) {
 		struct commit *parent = p->item;
-		printf(" %s", find_unique_abbrev(parent->object.oid.hash, abbrev));
+		fprintf(file, " %s", find_unique_abbrev(parent->object.oid.hash, abbrev));
 	}
 }
 
@@ -172,7 +172,7 @@ static void show_children(struct rev_info *opt, struct commit *commit, int abbre
 {
 	struct commit_list *p = lookup_decoration(&opt->children, &commit->object);
 	for ( ; p; p = p->next) {
-		printf(" %s", find_unique_abbrev(p->item->object.oid.hash, abbrev));
+		fprintf(opt->diffopt.file, " %s", find_unique_abbrev(p->item->object.oid.hash, abbrev));
 	}
 }
 
@@ -286,11 +286,11 @@ void show_decorations(struct rev_info *opt, struct commit *commit)
 	struct strbuf sb = STRBUF_INIT;
 
 	if (opt->show_source && commit->util)
-		printf("\t%s", (char *) commit->util);
+		fprintf(opt->diffopt.file, "\t%s", (char *) commit->util);
 	if (!opt->show_decorations)
 		return;
 	format_decorations(&sb, commit, opt->diffopt.use_color);
-	fputs(sb.buf, stdout);
+	fputs(sb.buf, opt->diffopt.file);
 	strbuf_release(&sb);
 }
 
@@ -364,18 +364,18 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
 		subject = "Subject: ";
 	}
 
-	printf("From %s Mon Sep 17 00:00:00 2001\n", name);
+	fprintf(opt->diffopt.file, "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);
+		fprintf(opt->diffopt.file, "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);
+		fprintf(opt->diffopt.file, "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: "),
+			fprintf(opt->diffopt.file, "%s<%s>\n", (i > 0 ? "\t" : "References: "),
 			       opt->ref_message_ids->items[i].string);
 		graph_show_oneline(opt->graph);
 	}
@@ -432,7 +432,7 @@ static void show_sig_lines(struct rev_info *opt, int status, const char *bol)
 	reset = diff_get_color_opt(&opt->diffopt, DIFF_RESET);
 	while (*bol) {
 		eol = strchrnul(bol, '\n');
-		printf("%s%.*s%s%s", color, (int)(eol - bol), bol, reset,
+		fprintf(opt->diffopt.file, "%s%.*s%s%s", color, (int)(eol - bol), bol, reset,
 		       *eol ? "\n" : "");
 		graph_show_oneline(opt->graph);
 		bol = (*eol) ? (eol + 1) : eol;
@@ -553,17 +553,17 @@ void show_log(struct rev_info *opt)
 
 		if (!opt->graph)
 			put_revision_mark(opt, commit);
-		fputs(find_unique_abbrev(commit->object.oid.hash, abbrev_commit), stdout);
+		fputs(find_unique_abbrev(commit->object.oid.hash, abbrev_commit), opt->diffopt.file);
 		if (opt->print_parents)
-			show_parents(commit, abbrev_commit);
+			show_parents(commit, abbrev_commit, opt->diffopt.file);
 		if (opt->children.name)
 			show_children(opt, commit, abbrev_commit);
 		show_decorations(opt, commit);
 		if (opt->graph && !graph_is_commit_finished(opt->graph)) {
-			putchar('\n');
+			putc('\n', opt->diffopt.file);
 			graph_show_remainder(opt->graph);
 		}
-		putchar(opt->diffopt.line_termination);
+		putc(opt->diffopt.line_termination, opt->diffopt.file);
 		return;
 	}
 
@@ -589,7 +589,7 @@ void show_log(struct rev_info *opt)
 		if (opt->diffopt.line_termination == '\n' &&
 		    !opt->missing_newline)
 			graph_show_padding(opt->graph);
-		putchar(opt->diffopt.line_termination);
+		putc(opt->diffopt.line_termination, opt->diffopt.file);
 	}
 	opt->shown_one = 1;
 
@@ -607,28 +607,28 @@ void show_log(struct rev_info *opt)
 		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(&opt->diffopt, DIFF_COMMIT), stdout);
+		fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), opt->diffopt.file);
 		if (opt->commit_format != CMIT_FMT_ONELINE)
-			fputs("commit ", stdout);
+			fputs("commit ", opt->diffopt.file);
 
 		if (!opt->graph)
 			put_revision_mark(opt, commit);
 		fputs(find_unique_abbrev(commit->object.oid.hash, abbrev_commit),
-		      stdout);
+		      opt->diffopt.file);
 		if (opt->print_parents)
-			show_parents(commit, abbrev_commit);
+			show_parents(commit, abbrev_commit, opt->diffopt.file);
 		if (opt->children.name)
 			show_children(opt, commit, abbrev_commit);
 		if (parent)
-			printf(" (from %s)",
+			fprintf(opt->diffopt.file, " (from %s)",
 			       find_unique_abbrev(parent->object.oid.hash,
 						  abbrev_commit));
-		fputs(diff_get_color_opt(&opt->diffopt, DIFF_RESET), stdout);
+		fputs(diff_get_color_opt(&opt->diffopt, DIFF_RESET), opt->diffopt.file);
 		show_decorations(opt, commit);
 		if (opt->commit_format == CMIT_FMT_ONELINE) {
-			putchar(' ');
+			putc(' ', opt->diffopt.file);
 		} else {
-			putchar('\n');
+			putc('\n', opt->diffopt.file);
 			graph_show_oneline(opt->graph);
 		}
 		if (opt->reflog_info) {
@@ -704,7 +704,7 @@ void show_log(struct rev_info *opt)
 	}
 
 	if (opt->show_log_size) {
-		printf("log size %i\n", (int)msgbuf.len);
+		fprintf(opt->diffopt.file, "log size %i\n", (int)msgbuf.len);
 		graph_show_oneline(opt->graph);
 	}
 
@@ -720,11 +720,11 @@ void show_log(struct rev_info *opt)
 	if (opt->graph)
 		graph_show_commit_msg(opt->graph, &msgbuf);
 	else
-		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
+		fwrite(msgbuf.buf, sizeof(char), msgbuf.len, opt->diffopt.file);
 	if (opt->use_terminator && !commit_format_is_empty(opt->commit_format)) {
 		if (!opt->missing_newline)
 			graph_show_padding(opt->graph);
-		putchar(opt->diffopt.line_termination);
+		putc(opt->diffopt.line_termination, opt->diffopt.file);
 	}
 
 	strbuf_release(&msgbuf);
@@ -761,7 +761,7 @@ int log_tree_diff_flush(struct rev_info *opt)
 				struct strbuf *msg = NULL;
 				msg = opt->diffopt.output_prefix(&opt->diffopt,
 					opt->diffopt.output_prefix_data);
-				fwrite(msg->buf, msg->len, 1, stdout);
+				fwrite(msg->buf, msg->len, 1, opt->diffopt.file);
 			}
 
 			/*
@@ -776,8 +776,8 @@ int log_tree_diff_flush(struct rev_info *opt)
 			 */
 			if (!opt->shown_dashes &&
 			    (pch & opt->diffopt.output_format) == pch)
-				printf("---");
-			putchar('\n');
+				fprintf(opt->diffopt.file, "---");
+			putc('\n', opt->diffopt.file);
 		}
 	}
 	diff_flush(&opt->diffopt);
@@ -864,17 +864,18 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
 int log_tree_commit(struct rev_info *opt, struct commit *commit)
 {
 	struct log_info log;
-	int shown;
+	int shown, close_file = opt->diffopt.close_file;
 
 	log.commit = commit;
 	log.parent = NULL;
 	opt->loginfo = &log;
+	opt->diffopt.close_file = 0;
 
 	if (opt->line_level_traverse)
 		return line_log_print(opt, commit);
 
 	if (opt->track_linear && !opt->linear && !opt->reverse_output_stage)
-		printf("\n%s\n", opt->break_bar);
+		fprintf(opt->diffopt.file, "\n%s\n", opt->break_bar);
 	shown = log_tree_diff(opt, commit, &log);
 	if (!shown && opt->loginfo && opt->always_show_header) {
 		log.parent = NULL;
@@ -882,8 +883,10 @@ int log_tree_commit(struct rev_info *opt, struct commit *commit)
 		shown = 1;
 	}
 	if (opt->track_linear && !opt->linear && opt->reverse_output_stage)
-		printf("\n%s\n", opt->break_bar);
+		fprintf(opt->diffopt.file, "\n%s\n", opt->break_bar);
 	opt->loginfo = NULL;
-	maybe_flush_or_die(stdout, "stdout");
+	maybe_flush_or_die(opt->diffopt.file, "stdout");
+	if (close_file)
+		fclose(opt->diffopt.file);
 	return shown;
 }
diff --git a/shortlog.h b/shortlog.h
index de4f86fb9..5a326c686 100644
--- a/shortlog.h
+++ b/shortlog.h
@@ -17,6 +17,7 @@ struct shortlog {
 	char *common_repo_prefix;
 	int email;
 	struct string_list mailmap;
+	FILE *file;
 };
 
 void shortlog_init(struct shortlog *log);
diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index a9773658f..ae08b5771 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -184,4 +184,10 @@ test_expect_success 'shortlog with revision pseudo options' '
 	git shortlog --exclude=refs/heads/m* --all
 '
 
+test_expect_success 'shortlog with --output=<file>' '
+	git shortlog --output=shortlog -1 master >output &&
+	test ! -s output &&
+	test_line_count = 3 shortlog
+'
+
 test_done
diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index 4451127eb..9d87777b5 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -99,4 +99,11 @@ test_expect_success '-L with --first-parent and a merge' '
 	git log --first-parent -L 1,1:b.c
 '
 
+test_expect_success '-L with --output' '
+	git checkout parallel-change &&
+	git log --output=log -L :main:b.c >output &&
+	test ! -s output &&
+	test_line_count = 70 log
+'
+
 test_done