mailinfo: move global "FILE *fin, *fout" to struct mailinfo

This requires us to pass "struct mailinfo" to more functions
throughout the codepath that read input lines.  Incidentally,
later steps are helped by this patch passing the struct to
more callchains.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/mailinfo.c

@@ -7,11 +7,14 @@
 #include "utf8.h"
 #include "strbuf.h"
 
-static FILE *cmitmsg, *patchfile, *fin, *fout;
+static FILE *cmitmsg, *patchfile;
 
 static const char *metainfo_charset;
 
 struct mailinfo {
+	FILE *input;
+	FILE *output;
+
 	struct strbuf name;
 	struct strbuf email;
 	int keep_subject;
@@ -788,16 +791,17 @@ static int read_one_header_line(struct strbuf *line, FILE *in)
 	return 1;
 }
 
-static int find_boundary(struct strbuf *line)
+static int find_boundary(struct mailinfo *mi, struct strbuf *line)
 {
-	while (!strbuf_getline(line, fin, '\n')) {
+	while (!strbuf_getline(line, mi->input, '\n')) {
 		if (*content_top && is_multipart_boundary(line))
 			return 1;
 	}
 	return 0;
 }
 
-static int handle_boundary(struct strbuf *line, int *filter_stage, int *header_stage)
+static int handle_boundary(struct mailinfo *mi, struct strbuf *line,
+			   int *filter_stage, int *header_stage)
 {
 	struct strbuf newline = STRBUF_INIT;
 
@@ -823,7 +827,7 @@ again:
 		strbuf_release(&newline);
 
 		/* skip to the next boundary */
-		if (!find_boundary(line))
+		if (!find_boundary(mi, line))
 			return 0;
 		goto again;
 	}
@@ -833,18 +837,18 @@ again:
 	strbuf_reset(&charset);
 
 	/* slurp in this section's info */
-	while (read_one_header_line(line, fin))
+	while (read_one_header_line(line, mi->input))
 		check_header(line, p_hdr_data, 0);
 
 	strbuf_release(&newline);
 	/* replenish line */
-	if (strbuf_getline(line, fin, '\n'))
+	if (strbuf_getline(line, mi->input, '\n'))
 		return 0;
 	strbuf_addch(line, '\n');
 	return 1;
 }
 
-static void handle_body(struct strbuf *line)
+static void handle_body(struct mailinfo *mi, struct strbuf *line)
 {
 	struct strbuf prev = STRBUF_INIT;
 	int filter_stage = 0;
@@ -852,7 +856,7 @@ static void handle_body(struct strbuf *line)
 
 	/* Skip up to the first boundary */
 	if (*content_top) {
-		if (!find_boundary(line))
+		if (!find_boundary(mi, line))
 			goto handle_body_out;
 	}
 
@@ -864,7 +868,7 @@ static void handle_body(struct strbuf *line)
 				handle_filter(&prev, &filter_stage, &header_stage);
 				strbuf_reset(&prev);
 			}
-			if (!handle_boundary(line, &filter_stage, &header_stage))
+			if (!handle_boundary(mi, line, &filter_stage, &header_stage))
 				goto handle_body_out;
 		}
 
@@ -907,7 +911,7 @@ static void handle_body(struct strbuf *line)
 			handle_filter(line, &filter_stage, &header_stage);
 		}
 
-	} while (!strbuf_getwholeline(line, fin, '\n'));
+	} while (!strbuf_getwholeline(line, mi->input, '\n'));
 
 handle_body_out:
 	strbuf_release(&prev);
@@ -949,29 +953,25 @@ static void handle_info(struct mailinfo *mi)
 				cleanup_subject(mi, hdr);
 				cleanup_space(hdr);
 			}
-			output_header_lines(fout, "Subject", hdr);
+			output_header_lines(mi->output, "Subject", hdr);
 		} else if (!strcmp(header[i], "From")) {
 			cleanup_space(hdr);
 			handle_from(mi, hdr);
-			fprintf(fout, "Author: %s\n", mi->name.buf);
-			fprintf(fout, "Email: %s\n", mi->email.buf);
+			fprintf(mi->output, "Author: %s\n", mi->name.buf);
+			fprintf(mi->output, "Email: %s\n", mi->email.buf);
 		} else {
 			cleanup_space(hdr);
-			fprintf(fout, "%s: %s\n", header[i], hdr->buf);
+			fprintf(mi->output, "%s: %s\n", header[i], hdr->buf);
 		}
 	}
-	fprintf(fout, "\n");
+	fprintf(mi->output, "\n");
 }
 
-static int mailinfo(struct mailinfo *mi,
-		    FILE *in, FILE *out, const char *msg, const char *patch)
+static int mailinfo(struct mailinfo *mi, const char *msg, const char *patch)
 {
 	int peek;
 	struct strbuf line = STRBUF_INIT;
 
-	fin = in;
-	fout = out;
-
 	cmitmsg = fopen(msg, "w");
 	if (!cmitmsg) {
 		perror(msg);
@@ -988,15 +988,15 @@ static int mailinfo(struct mailinfo *mi,
 	s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*s_hdr_data));
 
 	do {
-		peek = fgetc(in);
+		peek = fgetc(mi->input);
 	} while (isspace(peek));
-	ungetc(peek, in);
+	ungetc(peek, mi->input);
 
 	/* process the email header */
-	while (read_one_header_line(&line, fin))
+	while (read_one_header_line(&line, mi->input))
 		check_header(&line, p_hdr_data, 1);
 
-	handle_body(&line);
+	handle_body(mi, &line);
 	fclose(patchfile);
 
 	handle_info(mi);
@@ -1074,7 +1074,9 @@ int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 	if (argc != 3)
 		usage(mailinfo_usage);
 
-	status = !!mailinfo(&mi, stdin, stdout, argv[1], argv[2]);
+	mi.input = stdin;
+	mi.output = stdout;
+	status = !!mailinfo(&mi, argv[1], argv[2]);
 	clear_mailinfo(&mi);
 
 	return status;