mailinfo: libify
[gitweb.git] / builtin / mailinfo.c
index 999a5250fbe7e6d38a2c8927fa3c37233142ef19..f6df2741112144a38d048ebfd1fe201c8576a040 100644 (file)
 #include "builtin.h"
 #include "utf8.h"
 #include "strbuf.h"
-
-static FILE *cmitmsg, *patchfile, *fin, *fout;
-
-static int keep_subject;
-static int keep_non_patch_brackets_in_subject;
-static const char *metainfo_charset;
-static struct strbuf line = STRBUF_INIT;
-static struct strbuf name = STRBUF_INIT;
-static struct strbuf email = STRBUF_INIT;
-static char *message_id;
-
-static enum  {
-       TE_DONTCARE, TE_QP, TE_BASE64
-} transfer_encoding;
-
-static struct strbuf charset = STRBUF_INIT;
-static int patch_lines;
-static struct strbuf **p_hdr_data, **s_hdr_data;
-static int use_scissors;
-static int add_message_id;
-static int use_inbody_headers = 1;
-
-#define MAX_HDR_PARSED 10
-#define MAX_BOUNDARIES 5
-
-static void cleanup_space(struct strbuf *sb);
-
-
-static void get_sane_name(struct strbuf *out, struct strbuf *name, struct strbuf *email)
-{
-       struct strbuf *src = name;
-       if (name->len < 3 || 60 < name->len || strchr(name->buf, '@') ||
-               strchr(name->buf, '<') || strchr(name->buf, '>'))
-               src = email;
-       else if (name == out)
-               return;
-       strbuf_reset(out);
-       strbuf_addbuf(out, src);
-}
-
-static void parse_bogus_from(const struct strbuf *line)
-{
-       /* John Doe <johndoe> */
-
-       char *bra, *ket;
-       /* This is fallback, so do not bother if we already have an
-        * e-mail address.
-        */
-       if (email.len)
-               return;
-
-       bra = strchr(line->buf, '<');
-       if (!bra)
-               return;
-       ket = strchr(bra, '>');
-       if (!ket)
-               return;
-
-       strbuf_reset(&email);
-       strbuf_add(&email, bra + 1, ket - bra - 1);
-
-       strbuf_reset(&name);
-       strbuf_add(&name, line->buf, bra - line->buf);
-       strbuf_trim(&name);
-       get_sane_name(&name, &name, &email);
-}
-
-static void handle_from(const struct strbuf *from)
-{
-       char *at;
-       size_t el;
-       struct strbuf f;
-
-       strbuf_init(&f, from->len);
-       strbuf_addbuf(&f, from);
-
-       at = strchr(f.buf, '@');
-       if (!at) {
-               parse_bogus_from(from);
-               return;
-       }
-
-       /*
-        * If we already have one email, don't take any confusing lines
-        */
-       if (email.len && strchr(at + 1, '@')) {
-               strbuf_release(&f);
-               return;
-       }
-
-       /* Pick up the string around '@', possibly delimited with <>
-        * pair; that is the email part.
-        */
-       while (at > f.buf) {
-               char c = at[-1];
-               if (isspace(c))
-                       break;
-               if (c == '<') {
-                       at[-1] = ' ';
-                       break;
-               }
-               at--;
-       }
-       el = strcspn(at, " \n\t\r\v\f>");
-       strbuf_reset(&email);
-       strbuf_add(&email, at, el);
-       strbuf_remove(&f, at - f.buf, el + (at[el] ? 1 : 0));
-
-       /* The remainder is name.  It could be
-        *
-        * - "John Doe <john.doe@xz>"                   (a), or
-        * - "john.doe@xz (John Doe)"                   (b), or
-        * - "John (zzz) Doe <john.doe@xz> (Comment)"   (c)
-        *
-        * but we have removed the email part, so
-        *
-        * - remove extra spaces which could stay after email (case 'c'), and
-        * - trim from both ends, possibly removing the () pair at the end
-        *   (cases 'a' and 'b').
-        */
-       cleanup_space(&f);
-       strbuf_trim(&f);
-       if (f.buf[0] == '(' && f.len && f.buf[f.len - 1] == ')') {
-               strbuf_remove(&f, 0, 1);
-               strbuf_setlen(&f, f.len - 1);
-       }
-
-       get_sane_name(&name, &f, &email);
-       strbuf_release(&f);
-}
-
-static void handle_header(struct strbuf **out, const struct strbuf *line)
-{
-       if (!*out) {
-               *out = xmalloc(sizeof(struct strbuf));
-               strbuf_init(*out, line->len);
-       } else
-               strbuf_reset(*out);
-
-       strbuf_addbuf(*out, line);
-}
-
-/* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
- * to have enough heuristics to grok MIME encoded patches often found
- * on our mailing lists.  For example, we do not even treat header lines
- * case insensitively.
- */
-
-static int slurp_attr(const char *line, const char *name, struct strbuf *attr)
-{
-       const char *ends, *ap = strcasestr(line, name);
-       size_t sz;
-
-       strbuf_setlen(attr, 0);
-       if (!ap)
-               return 0;
-       ap += strlen(name);
-       if (*ap == '"') {
-               ap++;
-               ends = "\"";
-       }
-       else
-               ends = "; \t";
-       sz = strcspn(ap, ends);
-       strbuf_add(attr, ap, sz);
-       return 1;
-}
-
-static struct strbuf *content[MAX_BOUNDARIES];
-
-static struct strbuf **content_top = content;
-
-static void handle_content_type(struct strbuf *line)
-{
-       struct strbuf *boundary = xmalloc(sizeof(struct strbuf));
-       strbuf_init(boundary, line->len);
-
-       if (slurp_attr(line->buf, "boundary=", boundary)) {
-               strbuf_insert(boundary, 0, "--", 2);
-               if (++content_top > &content[MAX_BOUNDARIES]) {
-                       fprintf(stderr, "Too many boundaries to handle\n");
-                       exit(1);
-               }
-               *content_top = boundary;
-               boundary = NULL;
-       }
-       slurp_attr(line->buf, "charset=", &charset);
-
-       if (boundary) {
-               strbuf_release(boundary);
-               free(boundary);
-       }
-}
-
-static void handle_message_id(const struct strbuf *line)
-{
-       if (add_message_id)
-               message_id = strdup(line->buf);
-}
-
-static void handle_content_transfer_encoding(const struct strbuf *line)
-{
-       if (strcasestr(line->buf, "base64"))
-               transfer_encoding = TE_BASE64;
-       else if (strcasestr(line->buf, "quoted-printable"))
-               transfer_encoding = TE_QP;
-       else
-               transfer_encoding = TE_DONTCARE;
-}
-
-static int is_multipart_boundary(const struct strbuf *line)
-{
-       return (((*content_top)->len <= line->len) &&
-               !memcmp(line->buf, (*content_top)->buf, (*content_top)->len));
-}
-
-static void cleanup_subject(struct strbuf *subject)
-{
-       size_t at = 0;
-
-       while (at < subject->len) {
-               char *pos;
-               size_t remove;
-
-               switch (subject->buf[at]) {
-               case 'r': case 'R':
-                       if (subject->len <= at + 3)
-                               break;
-                       if ((subject->buf[at + 1] == 'e' ||
-                            subject->buf[at + 1] == 'E') &&
-                           subject->buf[at + 2] == ':') {
-                               strbuf_remove(subject, at, 3);
-                               continue;
-                       }
-                       at++;
-                       break;
-               case ' ': case '\t': case ':':
-                       strbuf_remove(subject, at, 1);
-                       continue;
-               case '[':
-                       pos = strchr(subject->buf + at, ']');
-                       if (!pos)
-                               break;
-                       remove = pos - subject->buf + at + 1;
-                       if (!keep_non_patch_brackets_in_subject ||
-                           (7 <= remove &&
-                            memmem(subject->buf + at, remove, "PATCH", 5)))
-                               strbuf_remove(subject, at, remove);
-                       else {
-                               at += remove;
-                               /*
-                                * If the input had a space after the ], keep
-                                * it.  We don't bother with finding the end of
-                                * the space, since we later normalize it
-                                * anyway.
-                                */
-                               if (isspace(subject->buf[at]))
-                                       at += 1;
-                       }
-                       continue;
-               }
-               break;
-       }
-       strbuf_trim(subject);
-}
-
-static void cleanup_space(struct strbuf *sb)
-{
-       size_t pos, cnt;
-       for (pos = 0; pos < sb->len; pos++) {
-               if (isspace(sb->buf[pos])) {
-                       sb->buf[pos] = ' ';
-                       for (cnt = 0; isspace(sb->buf[pos + cnt + 1]); cnt++);
-                       strbuf_remove(sb, pos + 1, cnt);
-               }
-       }
-}
-
-static void decode_header(struct strbuf *line);
-static const char *header[MAX_HDR_PARSED] = {
-       "From","Subject","Date",
-};
-
-static inline int cmp_header(const struct strbuf *line, const char *hdr)
-{
-       int len = strlen(hdr);
-       return !strncasecmp(line->buf, hdr, len) && line->len > len &&
-                       line->buf[len] == ':' && isspace(line->buf[len + 1]);
-}
-
-static int is_format_patch_separator(const char *line, int len)
-{
-       static const char SAMPLE[] =
-               "From e6807f3efca28b30decfecb1732a56c7db1137ee Mon Sep 17 00:00:00 2001\n";
-       const char *cp;
-
-       if (len != strlen(SAMPLE))
-               return 0;
-       if (!skip_prefix(line, "From ", &cp))
-               return 0;
-       if (strspn(cp, "0123456789abcdef") != 40)
-               return 0;
-       cp += 40;
-       return !memcmp(SAMPLE + (cp - line), cp, strlen(SAMPLE) - (cp - line));
-}
-
-static int check_header(const struct strbuf *line,
-                               struct strbuf *hdr_data[], int overwrite)
-{
-       int i, ret = 0, len;
-       struct strbuf sb = STRBUF_INIT;
-       /* search for the interesting parts */
-       for (i = 0; header[i]; i++) {
-               int len = strlen(header[i]);
-               if ((!hdr_data[i] || overwrite) && cmp_header(line, header[i])) {
-                       /* Unwrap inline B and Q encoding, and optionally
-                        * normalize the meta information to utf8.
-                        */
-                       strbuf_add(&sb, line->buf + len + 2, line->len - len - 2);
-                       decode_header(&sb);
-                       handle_header(&hdr_data[i], &sb);
-                       ret = 1;
-                       goto check_header_out;
-               }
-       }
-
-       /* Content stuff */
-       if (cmp_header(line, "Content-Type")) {
-               len = strlen("Content-Type: ");
-               strbuf_add(&sb, line->buf + len, line->len - len);
-               decode_header(&sb);
-               strbuf_insert(&sb, 0, "Content-Type: ", len);
-               handle_content_type(&sb);
-               ret = 1;
-               goto check_header_out;
-       }
-       if (cmp_header(line, "Content-Transfer-Encoding")) {
-               len = strlen("Content-Transfer-Encoding: ");
-               strbuf_add(&sb, line->buf + len, line->len - len);
-               decode_header(&sb);
-               handle_content_transfer_encoding(&sb);
-               ret = 1;
-               goto check_header_out;
-       }
-       if (cmp_header(line, "Message-Id")) {
-               len = strlen("Message-Id: ");
-               strbuf_add(&sb, line->buf + len, line->len - len);
-               decode_header(&sb);
-               handle_message_id(&sb);
-               ret = 1;
-               goto check_header_out;
-       }
-
-       /* for inbody stuff */
-       if (starts_with(line->buf, ">From") && isspace(line->buf[5])) {
-               ret = is_format_patch_separator(line->buf + 1, line->len - 1);
-               goto check_header_out;
-       }
-       if (starts_with(line->buf, "[PATCH]") && isspace(line->buf[7])) {
-               for (i = 0; header[i]; i++) {
-                       if (!strcmp("Subject", header[i])) {
-                               handle_header(&hdr_data[i], line);
-                               ret = 1;
-                               goto check_header_out;
-                       }
-               }
-       }
-
-check_header_out:
-       strbuf_release(&sb);
-       return ret;
-}
-
-static int is_rfc2822_header(const struct strbuf *line)
-{
-       /*
-        * The section that defines the loosest possible
-        * field name is "3.6.8 Optional fields".
-        *
-        * optional-field = field-name ":" unstructured CRLF
-        * field-name = 1*ftext
-        * ftext = %d33-57 / %59-126
-        */
-       int ch;
-       char *cp = line->buf;
-
-       /* Count mbox From headers as headers */
-       if (starts_with(cp, "From ") || starts_with(cp, ">From "))
-               return 1;
-
-       while ((ch = *cp++)) {
-               if (ch == ':')
-                       return 1;
-               if ((33 <= ch && ch <= 57) ||
-                   (59 <= ch && ch <= 126))
-                       continue;
-               break;
-       }
-       return 0;
-}
-
-static int read_one_header_line(struct strbuf *line, FILE *in)
-{
-       /* Get the first part of the line. */
-       if (strbuf_getline(line, in, '\n'))
-               return 0;
-
-       /*
-        * Is it an empty line or not a valid rfc2822 header?
-        * If so, stop here, and return false ("not a header")
-        */
-       strbuf_rtrim(line);
-       if (!line->len || !is_rfc2822_header(line)) {
-               /* Re-add the newline */
-               strbuf_addch(line, '\n');
-               return 0;
-       }
-
-       /*
-        * Now we need to eat all the continuation lines..
-        * Yuck, 2822 header "folding"
-        */
-       for (;;) {
-               int peek;
-               struct strbuf continuation = STRBUF_INIT;
-
-               peek = fgetc(in); ungetc(peek, in);
-               if (peek != ' ' && peek != '\t')
-                       break;
-               if (strbuf_getline(&continuation, in, '\n'))
-                       break;
-               continuation.buf[0] = ' ';
-               strbuf_rtrim(&continuation);
-               strbuf_addbuf(line, &continuation);
-       }
-
-       return 1;
-}
-
-static struct strbuf *decode_q_segment(const struct strbuf *q_seg, int rfc2047)
-{
-       const char *in = q_seg->buf;
-       int c;
-       struct strbuf *out = xmalloc(sizeof(struct strbuf));
-       strbuf_init(out, q_seg->len);
-
-       while ((c = *in++) != 0) {
-               if (c == '=') {
-                       int d = *in++;
-                       if (d == '\n' || !d)
-                               break; /* drop trailing newline */
-                       strbuf_addch(out, (hexval(d) << 4) | hexval(*in++));
-                       continue;
-               }
-               if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
-                       c = 0x20;
-               strbuf_addch(out, c);
-       }
-       return out;
-}
-
-static struct strbuf *decode_b_segment(const struct strbuf *b_seg)
-{
-       /* Decode in..ep, possibly in-place to ot */
-       int c, pos = 0, acc = 0;
-       const char *in = b_seg->buf;
-       struct strbuf *out = xmalloc(sizeof(struct strbuf));
-       strbuf_init(out, b_seg->len);
-
-       while ((c = *in++) != 0) {
-               if (c == '+')
-                       c = 62;
-               else if (c == '/')
-                       c = 63;
-               else if ('A' <= c && c <= 'Z')
-                       c -= 'A';
-               else if ('a' <= c && c <= 'z')
-                       c -= 'a' - 26;
-               else if ('0' <= c && c <= '9')
-                       c -= '0' - 52;
-               else
-                       continue; /* garbage */
-               switch (pos++) {
-               case 0:
-                       acc = (c << 2);
-                       break;
-               case 1:
-                       strbuf_addch(out, (acc | (c >> 4)));
-                       acc = (c & 15) << 4;
-                       break;
-               case 2:
-                       strbuf_addch(out, (acc | (c >> 2)));
-                       acc = (c & 3) << 6;
-                       break;
-               case 3:
-                       strbuf_addch(out, (acc | c));
-                       acc = pos = 0;
-                       break;
-               }
-       }
-       return out;
-}
-
-static void convert_to_utf8(struct strbuf *line, const char *charset)
-{
-       char *out;
-
-       if (!charset || !*charset)
-               return;
-
-       if (same_encoding(metainfo_charset, charset))
-               return;
-       out = reencode_string(line->buf, metainfo_charset, charset);
-       if (!out)
-               die("cannot convert from %s to %s",
-                   charset, metainfo_charset);
-       strbuf_attach(line, out, strlen(out), strlen(out));
-}
-
-static int decode_header_bq(struct strbuf *it)
-{
-       char *in, *ep, *cp;
-       struct strbuf outbuf = STRBUF_INIT, *dec;
-       struct strbuf charset_q = STRBUF_INIT, piecebuf = STRBUF_INIT;
-       int rfc2047 = 0;
-
-       in = it->buf;
-       while (in - it->buf <= it->len && (ep = strstr(in, "=?")) != NULL) {
-               int encoding;
-               strbuf_reset(&charset_q);
-               strbuf_reset(&piecebuf);
-               rfc2047 = 1;
-
-               if (in != ep) {
-                       /*
-                        * We are about to process an encoded-word
-                        * that begins at ep, but there is something
-                        * before the encoded word.
-                        */
-                       char *scan;
-                       for (scan = in; scan < ep; scan++)
-                               if (!isspace(*scan))
-                                       break;
-
-                       if (scan != ep || in == it->buf) {
-                               /*
-                                * We should not lose that "something",
-                                * unless we have just processed an
-                                * encoded-word, and there is only LWS
-                                * before the one we are about to process.
-                                */
-                               strbuf_add(&outbuf, in, ep - in);
-                       }
-               }
-               /* E.g.
-                * ep : "=?iso-2022-jp?B?GyR...?= foo"
-                * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
-                */
-               ep += 2;
-
-               if (ep - it->buf >= it->len || !(cp = strchr(ep, '?')))
-                       goto decode_header_bq_out;
-
-               if (cp + 3 - it->buf > it->len)
-                       goto decode_header_bq_out;
-               strbuf_add(&charset_q, ep, cp - ep);
-
-               encoding = cp[1];
-               if (!encoding || cp[2] != '?')
-                       goto decode_header_bq_out;
-               ep = strstr(cp + 3, "?=");
-               if (!ep)
-                       goto decode_header_bq_out;
-               strbuf_add(&piecebuf, cp + 3, ep - cp - 3);
-               switch (tolower(encoding)) {
-               default:
-                       goto decode_header_bq_out;
-               case 'b':
-                       dec = decode_b_segment(&piecebuf);
-                       break;
-               case 'q':
-                       dec = decode_q_segment(&piecebuf, 1);
-                       break;
-               }
-               if (metainfo_charset)
-                       convert_to_utf8(dec, charset_q.buf);
-
-               strbuf_addbuf(&outbuf, dec);
-               strbuf_release(dec);
-               free(dec);
-               in = ep + 2;
-       }
-       strbuf_addstr(&outbuf, in);
-       strbuf_reset(it);
-       strbuf_addbuf(it, &outbuf);
-decode_header_bq_out:
-       strbuf_release(&outbuf);
-       strbuf_release(&charset_q);
-       strbuf_release(&piecebuf);
-       return rfc2047;
-}
-
-static void decode_header(struct strbuf *it)
-{
-       if (decode_header_bq(it))
-               return;
-       /* otherwise "it" is a straight copy of the input.
-        * This can be binary guck but there is no charset specified.
-        */
-       if (metainfo_charset)
-               convert_to_utf8(it, "");
-}
-
-static void decode_transfer_encoding(struct strbuf *line)
-{
-       struct strbuf *ret;
-
-       switch (transfer_encoding) {
-       case TE_QP:
-               ret = decode_q_segment(line, 0);
-               break;
-       case TE_BASE64:
-               ret = decode_b_segment(line);
-               break;
-       case TE_DONTCARE:
-       default:
-               return;
-       }
-       strbuf_reset(line);
-       strbuf_addbuf(line, ret);
-       strbuf_release(ret);
-       free(ret);
-}
-
-static void handle_filter(struct strbuf *line);
-
-static int find_boundary(void)
-{
-       while (!strbuf_getline(&line, fin, '\n')) {
-               if (*content_top && is_multipart_boundary(&line))
-                       return 1;
-       }
-       return 0;
-}
-
-static int handle_boundary(void)
-{
-       struct strbuf newline = STRBUF_INIT;
-
-       strbuf_addch(&newline, '\n');
-again:
-       if (line.len >= (*content_top)->len + 2 &&
-           !memcmp(line.buf + (*content_top)->len, "--", 2)) {
-               /* we hit an end boundary */
-               /* pop the current boundary off the stack */
-               strbuf_release(*content_top);
-               free(*content_top);
-               *content_top = NULL;
-
-               /* technically won't happen as is_multipart_boundary()
-                  will fail first.  But just in case..
-                */
-               if (--content_top < content) {
-                       fprintf(stderr, "Detected mismatched boundaries, "
-                                       "can't recover\n");
-                       exit(1);
-               }
-               handle_filter(&newline);
-               strbuf_release(&newline);
-
-               /* skip to the next boundary */
-               if (!find_boundary())
-                       return 0;
-               goto again;
-       }
-
-       /* set some defaults */
-       transfer_encoding = TE_DONTCARE;
-       strbuf_reset(&charset);
-
-       /* slurp in this section's info */
-       while (read_one_header_line(&line, fin))
-               check_header(&line, p_hdr_data, 0);
-
-       strbuf_release(&newline);
-       /* replenish line */
-       if (strbuf_getline(&line, fin, '\n'))
-               return 0;
-       strbuf_addch(&line, '\n');
-       return 1;
-}
-
-static inline int patchbreak(const struct strbuf *line)
-{
-       size_t i;
-
-       /* Beginning of a "diff -" header? */
-       if (starts_with(line->buf, "diff -"))
-               return 1;
-
-       /* CVS "Index: " line? */
-       if (starts_with(line->buf, "Index: "))
-               return 1;
-
-       /*
-        * "--- <filename>" starts patches without headers
-        * "---<sp>*" is a manual separator
-        */
-       if (line->len < 4)
-               return 0;
-
-       if (starts_with(line->buf, "---")) {
-               /* space followed by a filename? */
-               if (line->buf[3] == ' ' && !isspace(line->buf[4]))
-                       return 1;
-               /* Just whitespace? */
-               for (i = 3; i < line->len; i++) {
-                       unsigned char c = line->buf[i];
-                       if (c == '\n')
-                               return 1;
-                       if (!isspace(c))
-                               break;
-               }
-               return 0;
-       }
-       return 0;
-}
-
-static int is_scissors_line(const struct strbuf *line)
-{
-       size_t i, len = line->len;
-       int scissors = 0, gap = 0;
-       int first_nonblank = -1;
-       int last_nonblank = 0, visible, perforation = 0, in_perforation = 0;
-       const char *buf = line->buf;
-
-       for (i = 0; i < len; i++) {
-               if (isspace(buf[i])) {
-                       if (in_perforation) {
-                               perforation++;
-                               gap++;
-                       }
-                       continue;
-               }
-               last_nonblank = i;
-               if (first_nonblank < 0)
-                       first_nonblank = i;
-               if (buf[i] == '-') {
-                       in_perforation = 1;
-                       perforation++;
-                       continue;
-               }
-               if (i + 1 < len &&
-                   (!memcmp(buf + i, ">8", 2) || !memcmp(buf + i, "8<", 2) ||
-                    !memcmp(buf + i, ">%", 2) || !memcmp(buf + i, "%<", 2))) {
-                       in_perforation = 1;
-                       perforation += 2;
-                       scissors += 2;
-                       i++;
-                       continue;
-               }
-               in_perforation = 0;
-       }
-
-       /*
-        * The mark must be at least 8 bytes long (e.g. "-- >8 --").
-        * Even though there can be arbitrary cruft on the same line
-        * (e.g. "cut here"), in order to avoid misidentification, the
-        * perforation must occupy more than a third of the visible
-        * width of the line, and dashes and scissors must occupy more
-        * than half of the perforation.
-        */
-
-       visible = last_nonblank - first_nonblank + 1;
-       return (scissors && 8 <= visible &&
-               visible < perforation * 3 &&
-               gap * 2 < perforation);
-}
-
-static int handle_commit_msg(struct strbuf *line)
-{
-       static int still_looking = 1;
-
-       if (!cmitmsg)
-               return 0;
-
-       if (still_looking) {
-               if (!line->len || (line->len == 1 && line->buf[0] == '\n'))
-                       return 0;
-       }
-
-       if (use_inbody_headers && still_looking) {
-               still_looking = check_header(line, s_hdr_data, 0);
-               if (still_looking)
-                       return 0;
-       } else
-               /* Only trim the first (blank) line of the commit message
-                * when ignoring in-body headers.
-                */
-               still_looking = 0;
-
-       /* normalize the log message to UTF-8. */
-       if (metainfo_charset)
-               convert_to_utf8(line, charset.buf);
-
-       if (use_scissors && is_scissors_line(line)) {
-               int i;
-               if (fseek(cmitmsg, 0L, SEEK_SET))
-                       die_errno("Could not rewind output message file");
-               if (ftruncate(fileno(cmitmsg), 0))
-                       die_errno("Could not truncate output message file at scissors");
-               still_looking = 1;
-
-               /*
-                * We may have already read "secondary headers"; purge
-                * them to give ourselves a clean restart.
-                */
-               for (i = 0; header[i]; i++) {
-                       if (s_hdr_data[i])
-                               strbuf_release(s_hdr_data[i]);
-                       s_hdr_data[i] = NULL;
-               }
-               return 0;
-       }
-
-       if (patchbreak(line)) {
-               if (message_id)
-                       fprintf(cmitmsg, "Message-Id: %s\n", message_id);
-               fclose(cmitmsg);
-               cmitmsg = NULL;
-               return 1;
-       }
-
-       fputs(line->buf, cmitmsg);
-       return 0;
-}
-
-static void handle_patch(const struct strbuf *line)
-{
-       fwrite(line->buf, 1, line->len, patchfile);
-       patch_lines++;
-}
-
-static void handle_filter(struct strbuf *line)
-{
-       static int filter = 0;
-
-       /* filter tells us which part we left off on */
-       switch (filter) {
-       case 0:
-               if (!handle_commit_msg(line))
-                       break;
-               filter++;
-       case 1:
-               handle_patch(line);
-               break;
-       }
-}
-
-static void handle_body(void)
-{
-       struct strbuf prev = STRBUF_INIT;
-
-       /* Skip up to the first boundary */
-       if (*content_top) {
-               if (!find_boundary())
-                       goto handle_body_out;
-       }
-
-       do {
-               /* process any boundary lines */
-               if (*content_top && is_multipart_boundary(&line)) {
-                       /* flush any leftover */
-                       if (prev.len) {
-                               handle_filter(&prev);
-                               strbuf_reset(&prev);
-                       }
-                       if (!handle_boundary())
-                               goto handle_body_out;
-               }
-
-               /* Unwrap transfer encoding */
-               decode_transfer_encoding(&line);
-
-               switch (transfer_encoding) {
-               case TE_BASE64:
-               case TE_QP:
-               {
-                       struct strbuf **lines, **it, *sb;
-
-                       /* Prepend any previous partial lines */
-                       strbuf_insert(&line, 0, prev.buf, prev.len);
-                       strbuf_reset(&prev);
-
-                       /*
-                        * This is a decoded line that may contain
-                        * multiple new lines.  Pass only one chunk
-                        * at a time to handle_filter()
-                        */
-                       lines = strbuf_split(&line, '\n');
-                       for (it = lines; (sb = *it); it++) {
-                               if (*(it + 1) == NULL) /* The last line */
-                                       if (sb->buf[sb->len - 1] != '\n') {
-                                               /* Partial line, save it for later. */
-                                               strbuf_addbuf(&prev, sb);
-                                               break;
-                                       }
-                               handle_filter(sb);
-                       }
-                       /*
-                        * The partial chunk is saved in "prev" and will be
-                        * appended by the next iteration of read_line_with_nul().
-                        */
-                       strbuf_list_free(lines);
-                       break;
-               }
-               default:
-                       handle_filter(&line);
-               }
-
-       } while (!strbuf_getwholeline(&line, fin, '\n'));
-
-handle_body_out:
-       strbuf_release(&prev);
-}
-
-static void output_header_lines(FILE *fout, const char *hdr, const struct strbuf *data)
-{
-       const char *sp = data->buf;
-       while (1) {
-               char *ep = strchr(sp, '\n');
-               int len;
-               if (!ep)
-                       len = strlen(sp);
-               else
-                       len = ep - sp;
-               fprintf(fout, "%s: %.*s\n", hdr, len, sp);
-               if (!ep)
-                       break;
-               sp = ep + 1;
-       }
-}
-
-static void handle_info(void)
-{
-       struct strbuf *hdr;
-       int i;
-
-       for (i = 0; header[i]; i++) {
-               /* only print inbody headers if we output a patch file */
-               if (patch_lines && s_hdr_data[i])
-                       hdr = s_hdr_data[i];
-               else if (p_hdr_data[i])
-                       hdr = p_hdr_data[i];
-               else
-                       continue;
-
-               if (!strcmp(header[i], "Subject")) {
-                       if (!keep_subject) {
-                               cleanup_subject(hdr);
-                               cleanup_space(hdr);
-                       }
-                       output_header_lines(fout, "Subject", hdr);
-               } else if (!strcmp(header[i], "From")) {
-                       cleanup_space(hdr);
-                       handle_from(hdr);
-                       fprintf(fout, "Author: %s\n", name.buf);
-                       fprintf(fout, "Email: %s\n", email.buf);
-               } else {
-                       cleanup_space(hdr);
-                       fprintf(fout, "%s: %s\n", header[i], hdr->buf);
-               }
-       }
-       fprintf(fout, "\n");
-}
-
-static int mailinfo(FILE *in, FILE *out, const char *msg, const char *patch)
-{
-       int peek;
-       fin = in;
-       fout = out;
-
-       cmitmsg = fopen(msg, "w");
-       if (!cmitmsg) {
-               perror(msg);
-               return -1;
-       }
-       patchfile = fopen(patch, "w");
-       if (!patchfile) {
-               perror(patch);
-               fclose(cmitmsg);
-               return -1;
-       }
-
-       p_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*p_hdr_data));
-       s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*s_hdr_data));
-
-       do {
-               peek = fgetc(in);
-       } while (isspace(peek));
-       ungetc(peek, in);
-
-       /* process the email header */
-       while (read_one_header_line(&line, fin))
-               check_header(&line, p_hdr_data, 1);
-
-       handle_body();
-       handle_info();
-
-       return 0;
-}
-
-static int git_mailinfo_config(const char *var, const char *value, void *unused)
-{
-       if (!starts_with(var, "mailinfo."))
-               return git_default_config(var, value, unused);
-       if (!strcmp(var, "mailinfo.scissors")) {
-               use_scissors = git_config_bool(var, value);
-               return 0;
-       }
-       /* perhaps others here */
-       return 0;
-}
+#include "mailinfo.h"
 
 static const char mailinfo_usage[] =
        "git mailinfo [-k | -b] [-m | --message-id] [-u | --encoding=<encoding> | -n] [--scissors | --no-scissors] <msg> <patch> < mail >info";
@@ -1036,34 +14,36 @@ static const char mailinfo_usage[] =
 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 {
        const char *def_charset;
+       struct mailinfo mi;
+       int status;
 
        /* NEEDSWORK: might want to do the optional .git/ directory
         * discovery
         */
-       git_config(git_mailinfo_config, NULL);
+       setup_mailinfo(&mi);
 
        def_charset = get_commit_output_encoding();
-       metainfo_charset = def_charset;
+       mi.metainfo_charset = def_charset;
 
        while (1 < argc && argv[1][0] == '-') {
                if (!strcmp(argv[1], "-k"))
-                       keep_subject = 1;
+                       mi.keep_subject = 1;
                else if (!strcmp(argv[1], "-b"))
-                       keep_non_patch_brackets_in_subject = 1;
+                       mi.keep_non_patch_brackets_in_subject = 1;
                else if (!strcmp(argv[1], "-m") || !strcmp(argv[1], "--message-id"))
-                       add_message_id = 1;
+                       mi.add_message_id = 1;
                else if (!strcmp(argv[1], "-u"))
-                       metainfo_charset = def_charset;
+                       mi.metainfo_charset = def_charset;
                else if (!strcmp(argv[1], "-n"))
-                       metainfo_charset = NULL;
+                       mi.metainfo_charset = NULL;
                else if (starts_with(argv[1], "--encoding="))
-                       metainfo_charset = argv[1] + 11;
+                       mi.metainfo_charset = argv[1] + 11;
                else if (!strcmp(argv[1], "--scissors"))
-                       use_scissors = 1;
+                       mi.use_scissors = 1;
                else if (!strcmp(argv[1], "--no-scissors"))
-                       use_scissors = 0;
+                       mi.use_scissors = 0;
                else if (!strcmp(argv[1], "--no-inbody-headers"))
-                       use_inbody_headers = 0;
+                       mi.use_inbody_headers = 0;
                else
                        usage(mailinfo_usage);
                argc--; argv++;
@@ -1072,5 +52,10 @@ int cmd_mailinfo(int argc, const char **argv, const char *prefix)
        if (argc != 3)
                usage(mailinfo_usage);
 
-       return !!mailinfo(stdin, stdout, argv[1], argv[2]);
+       mi.input = stdin;
+       mi.output = stdout;
+       status = !!mailinfo(&mi, argv[1], argv[2]);
+       clear_mailinfo(&mi);
+
+       return status;
 }