log-tree: respect diffopt's configured output file stream

The diff options already know how to print the output anywhere else
than stdout. The same is needed for log output in general, e.g.
when writing patches to files in `git format-patch`. Let's allow
users to use log_tree_commit() *without* changing global state via
freopen().
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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) {
@@ -702,7 +702,7 @@ 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);
 	}
 
@@ -718,11 +718,11 @@ 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);
@@ -759,7 +759,7 @@ 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);
 			}
 
 			/*
@@ -774,8 +774,8 @@ 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);
@@ -873,7 +873,7 @@ int log_tree_commit(struct rev_info *opt, struct commit *commit)
 		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;
@@ -881,9 +881,9 @@ 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;