Git 2.7
[gitweb.git] / mailinfo.c
index 0ccd490082455590f11e44cda5ce199dd56b9ed9..f289941f7e516be2f6265326188b3d8da70ef3aa 100644 (file)
@@ -1,98 +1,86 @@
-/*
- * Another stupid program, this one parsing the headers of an
- * email to figure out authorship and subject
- */
-#define _GNU_SOURCE
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
-#ifndef NO_ICONV
-#include <iconv.h>
-#endif
-#include "git-compat-util.h"
 #include "cache.h"
+#include "utf8.h"
+#include "strbuf.h"
+#include "mailinfo.h"
 
-static FILE *cmitmsg, *patchfile;
-
-static int keep_subject = 0;
-static char *metainfo_charset = NULL;
-static char line[1000];
-static char date[1000];
-static char name[1000];
-static char email[1000];
-static char subject[1000];
-
-static enum  {
-       TE_DONTCARE, TE_QP, TE_BASE64,
-} transfer_encoding;
-static char charset[256];
-
-static char multipart_boundary[1000];
-static int multipart_boundary_len;
-static int patch_lines = 0;
+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 char *sanity_check(char *name, char *email)
+static void get_sane_name(struct strbuf *out, struct strbuf *name, struct strbuf *email)
 {
-       int len = strlen(name);
-       if (len < 3 || len > 60)
-               return email;
-       if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
-               return email;
-       return name;
+       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 int bogus_from(char *line)
+static void parse_bogus_from(struct mailinfo *mi, const struct strbuf *line)
 {
        /* John Doe <johndoe> */
-       char *bra, *ket, *dst, *cp;
 
+       char *bra, *ket;
        /* This is fallback, so do not bother if we already have an
         * e-mail address.
-        */ 
-       if (*email)
-               return 0;
+        */
+       if (mi->email.len)
+               return;
 
-       bra = strchr(line, '<');
+       bra = strchr(line->buf, '<');
        if (!bra)
-               return 0;
+               return;
        ket = strchr(bra, '>');
        if (!ket)
-               return 0;
+               return;
 
-       for (dst = email, cp = bra+1; cp < ket; )
-               *dst++ = *cp++;
-       *dst = 0;
-       for (cp = line; isspace(*cp); cp++)
-               ;
-       for (bra--; isspace(*bra); bra--)
-               *bra = 0;
-       cp = sanity_check(cp, email);
-       strcpy(name, cp);
-       return 1;
+       strbuf_reset(&mi->email);
+       strbuf_add(&mi->email, bra + 1, ket - bra - 1);
+
+       strbuf_reset(&mi->name);
+       strbuf_add(&mi->name, line->buf, bra - line->buf);
+       strbuf_trim(&mi->name);
+       get_sane_name(&mi->name, &mi->name, &mi->email);
 }
 
-static int handle_from(char *in_line)
+static void handle_from(struct mailinfo *mi, const struct strbuf *from)
 {
-       char line[1000];
        char *at;
-       char *dst;
+       size_t el;
+       struct strbuf f;
 
-       strcpy(line, in_line);
-       at = strchr(line, '@');
-       if (!at)
-               return bogus_from(line);
+       strbuf_init(&f, from->len);
+       strbuf_addbuf(&f, from);
+
+       at = strchr(f.buf, '@');
+       if (!at) {
+               parse_bogus_from(mi, from);
+               return;
+       }
 
        /*
         * If we already have one email, don't take any confusing lines
         */
-       if (*email && strchr(at+1, '@'))
-               return 0;
+       if (mi->email.len && strchr(at + 1, '@')) {
+               strbuf_release(&f);
+               return;
+       }
 
        /* Pick up the string around '@', possibly delimited with <>
-        * pair; that is the email part.  White them out while copying.
+        * pair; that is the email part.
         */
-       while (at > line) {
+       while (at > f.buf) {
                char c = at[-1];
                if (isspace(c))
                        break;
@@ -102,58 +90,43 @@ static int handle_from(char *in_line)
                }
                at--;
        }
-       dst = email;
-       for (;;) {
-               unsigned char c = *at;
-               if (!c || c == '>' || isspace(c)) {
-                       if (c == '>')
-                               *at = ' ';
-                       break;
-               }
-               *at++ = ' ';
-               *dst++ = c;
-       }
-       *dst++ = 0;
+       el = strcspn(at, " \n\t\r\v\f>");
+       strbuf_reset(&mi->email);
+       strbuf_add(&mi->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>"
-        * or "john.doe@xz (John Doe)", but we have whited out the
-        * email part, so trim from both ends, possibly removing
-        * the () pair at the end.
+       /* 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').
         */
-       at = line + strlen(line);
-       while (at > line) {
-               unsigned char c = *--at;
-               if (!isspace(c)) {
-                       at[(c == ')') ? 0 : 1] = 0;
-                       break;
-               }
+       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);
        }
 
-       at = line;
-       for (;;) {
-               unsigned char c = *at;
-               if (!c || !isspace(c)) {
-                       if (c == '(')
-                               at++;
-                       break;
-               }
-               at++;
-       }
-       at = sanity_check(at, email);
-       strcpy(name, at);
-       return 1;
+       get_sane_name(&mi->name, &f, &mi->email);
+       strbuf_release(&f);
 }
 
-static int handle_date(char *line)
+static void handle_header(struct strbuf **out, const struct strbuf *line)
 {
-       strcpy(date, line);
-       return 0;
-}
+       if (!*out) {
+               *out = xmalloc(sizeof(struct strbuf));
+               strbuf_init(*out, line->len);
+       } else
+               strbuf_reset(*out);
 
-static int handle_subject(char *line)
-{
-       strcpy(subject, line);
-       return 0;
+       strbuf_addbuf(*out, line);
 }
 
 /* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
@@ -162,15 +135,14 @@ static int handle_subject(char *line)
  * case insensitively.
  */
 
-static int slurp_attr(const char *line, const char *name, char *attr)
+static int slurp_attr(const char *line, const char *name, struct strbuf *attr)
 {
-       char *ends, *ap = strcasestr(line, name);
+       const char *ends, *ap = strcasestr(line, name);
        size_t sz;
 
-       if (!ap) {
-               *attr = 0;
+       strbuf_setlen(attr, 0);
+       if (!ap)
                return 0;
-       }
        ap += strlen(name);
        if (*ap == '"') {
                ap++;
@@ -179,305 +151,168 @@ static int slurp_attr(const char *line, const char *name, char *attr)
        else
                ends = "; \t";
        sz = strcspn(ap, ends);
-       memcpy(attr, ap, sz);
-       attr[sz] = 0;
+       strbuf_add(attr, ap, sz);
        return 1;
 }
 
-static int handle_subcontent_type(char *line)
+static void handle_content_type(struct mailinfo *mi, struct strbuf *line)
 {
-       /* We do not want to mess with boundary.  Note that we do not
-        * handle nested multipart.
-        */
-       if (strcasestr(line, "boundary=")) {
-               fprintf(stderr, "Not handling nested multipart message.\n");
-               exit(1);
+       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 (++mi->content_top >= &mi->content[MAX_BOUNDARIES]) {
+                       error("Too many boundaries to handle");
+                       mi->input_error = -1;
+                       mi->content_top = &mi->content[MAX_BOUNDARIES] - 1;
+                       return;
+               }
+               *(mi->content_top) = boundary;
+               boundary = NULL;
        }
-       slurp_attr(line, "charset=", charset);
-       if (*charset) {
-               int i, c;
-               for (i = 0; (c = charset[i]) != 0; i++)
-                       charset[i] = tolower(c);
+       slurp_attr(line->buf, "charset=", &mi->charset);
+
+       if (boundary) {
+               strbuf_release(boundary);
+               free(boundary);
        }
-       return 0;
 }
 
-static int handle_content_type(char *line)
+static void handle_message_id(struct mailinfo *mi, const struct strbuf *line)
 {
-       *multipart_boundary = 0;
-       if (slurp_attr(line, "boundary=", multipart_boundary + 2)) {
-               memcpy(multipart_boundary, "--", 2);
-               multipart_boundary_len = strlen(multipart_boundary);
-       }
-       slurp_attr(line, "charset=", charset);
-       return 0;
+       if (mi->add_message_id)
+               mi->message_id = strdup(line->buf);
 }
 
-static int handle_content_transfer_encoding(char *line)
+static void handle_content_transfer_encoding(struct mailinfo *mi,
+                                            const struct strbuf *line)
 {
-       if (strcasestr(line, "base64"))
-               transfer_encoding = TE_BASE64;
-       else if (strcasestr(line, "quoted-printable"))
-               transfer_encoding = TE_QP;
+       if (strcasestr(line->buf, "base64"))
+               mi->transfer_encoding = TE_BASE64;
+       else if (strcasestr(line->buf, "quoted-printable"))
+               mi->transfer_encoding = TE_QP;
        else
-               transfer_encoding = TE_DONTCARE;
-       return 0;
+               mi->transfer_encoding = TE_DONTCARE;
 }
 
-static int is_multipart_boundary(const char *line)
+static int is_multipart_boundary(struct mailinfo *mi, const struct strbuf *line)
 {
-       return (!memcmp(line, multipart_boundary, multipart_boundary_len));
-}
+       struct strbuf *content_top = *(mi->content_top);
 
-static int eatspace(char *line)
-{
-       int len = strlen(line);
-       while (len > 0 && isspace(line[len-1]))
-               line[--len] = 0;
-       return len;
+       return ((content_top->len <= line->len) &&
+               !memcmp(line->buf, content_top->buf, content_top->len));
 }
 
-#define SEEN_FROM 01
-#define SEEN_DATE 02
-#define SEEN_SUBJECT 04
-#define SEEN_BOGUS_UNIX_FROM 010
-#define SEEN_PREFIX  020
-
-/* First lines of body can have From:, Date:, and Subject: */
-static void handle_inbody_header(int *seen, char *line)
+static void cleanup_subject(struct mailinfo *mi, struct strbuf *subject)
 {
-       if (*seen & SEEN_PREFIX)
-               return;
-       if (!memcmp(">From", line, 5) && isspace(line[5])) {
-               if (!(*seen & SEEN_BOGUS_UNIX_FROM)) {
-                       *seen |= SEEN_BOGUS_UNIX_FROM;
-                       return;
-               }
-       }
-       if (!memcmp("From:", line, 5) && isspace(line[5])) {
-               if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
-                       *seen |= SEEN_FROM;
-                       return;
-               }
-       }
-       if (!memcmp("Date:", line, 5) && isspace(line[5])) {
-               if (!(*seen & SEEN_DATE)) {
-                       handle_date(line+6);
-                       *seen |= SEEN_DATE;
-                       return;
-               }
-       }
-       if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
-               if (!(*seen & SEEN_SUBJECT)) {
-                       handle_subject(line+9);
-                       *seen |= SEEN_SUBJECT;
-                       return;
-               }
-       }
-       if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
-               if (!(*seen & SEEN_SUBJECT)) {
-                       handle_subject(line);
-                       *seen |= SEEN_SUBJECT;
-                       return;
-               }
-       }
-       *seen |= SEEN_PREFIX;
-}
+       size_t at = 0;
 
-static char *cleanup_subject(char *subject)
-{
-       if (keep_subject)
-               return subject;
-       for (;;) {
-               char *p;
-               int len, remove;
-               switch (*subject) {
+       while (at < subject->len) {
+               char *pos;
+               size_t remove;
+
+               switch (subject->buf[at]) {
                case 'r': case 'R':
-                       if (!memcmp("e:", subject+1, 2)) {
-                               subject +=3;
+                       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 ':':
-                       subject++;
+                       strbuf_remove(subject, at, 1);
                        continue;
-
                case '[':
-                       p = strchr(subject, ']');
-                       if (!p) {
-                               subject++;
-                               continue;
-                       }
-                       len = strlen(p);
-                       remove = p - subject;
-                       if (remove <= len *2) {
-                               subject = p+1;
-                               continue;
-                       }       
-                       break;
-               }
-               return subject;
-       }
-}                      
-
-static void cleanup_space(char *buf)
-{
-       unsigned char c;
-       while ((c = *buf) != 0) {
-               buf++;
-               if (isspace(c)) {
-                       buf[-1] = ' ';
-                       c = *buf;
-                       while (isspace(c)) {
-                               int len = strlen(buf);
-                               memmove(buf, buf+1, len);
-                               c = *buf;
+                       pos = strchr(subject->buf + at, ']');
+                       if (!pos)
+                               break;
+                       remove = pos - subject->buf + at + 1;
+                       if (!mi->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 decode_header_bq(char *it);
-typedef int (*header_fn_t)(char *);
-struct header_def {
-       const char *name;
-       header_fn_t func;
-       int namelen;
+#define MAX_HDR_PARSED 10
+static const char *header[MAX_HDR_PARSED] = {
+       "From","Subject","Date",
 };
 
-static void check_header(char *line, struct header_def *header)
+static inline int cmp_header(const struct strbuf *line, const char *hdr)
 {
-       int i;
-
-       if (header[0].namelen <= 0) {
-               for (i = 0; header[i].name; i++)
-                       header[i].namelen = strlen(header[i].name);
-       }
-       for (i = 0; header[i].name; i++) {
-               int len = header[i].namelen;
-               if (!strncasecmp(line, header[i].name, len) &&
-                   line[len] == ':' && isspace(line[len + 1])) {
-                       /* Unwrap inline B and Q encoding, and optionally
-                        * normalize the meta information to utf8.
-                        */
-                       decode_header_bq(line + len + 2);
-                       header[i].func(line + len + 2);
-                       break;
-               }
-       }
+       int len = strlen(hdr);
+       return !strncasecmp(line->buf, hdr, len) && line->len > len &&
+                       line->buf[len] == ':' && isspace(line->buf[len + 1]);
 }
 
-static void check_subheader_line(char *line)
-{
-       static struct header_def header[] = {
-               { "Content-Type", handle_subcontent_type },
-               { "Content-Transfer-Encoding",
-                 handle_content_transfer_encoding },
-               { NULL },
-       };
-       check_header(line, header);
-}
-static void check_header_line(char *line)
+static int is_format_patch_separator(const char *line, int len)
 {
-       static struct header_def header[] = {
-               { "From", handle_from },
-               { "Date", handle_date },
-               { "Subject", handle_subject },
-               { "Content-Type", handle_content_type },
-               { "Content-Transfer-Encoding",
-                 handle_content_transfer_encoding },
-               { NULL },
-       };
-       check_header(line, header);
-}
+       static const char SAMPLE[] =
+               "From e6807f3efca28b30decfecb1732a56c7db1137ee Mon Sep 17 00:00:00 2001\n";
+       const char *cp;
 
-static int is_rfc2822_header(char *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;
-       while ((ch = *cp++)) {
-               if (ch == ':')
-                       return cp != line;
-               if ((33 <= ch && ch <= 57) ||
-                   (59 <= ch && ch <= 126))
-                       continue;
-               break;
-       }
-       return 0;
-}
-
-static int read_one_header_line(char *line, int sz, FILE *in)
-{
-       int ofs = 0;
-       while (ofs < sz) {
-               int peek, len;
-               if (fgets(line + ofs, sz - ofs, in) == NULL)
-                       break;
-               len = eatspace(line + ofs);
-               if (len == 0)
-                       break;
-               if (!is_rfc2822_header(line)) {
-                       /* Re-add the newline */
-                       line[ofs + len] = '\n';
-                       line[ofs + len + 1] = '\0';
-                       break;
-               }
-               ofs += len;
-               /* Yuck, 2822 header "folding" */
-               peek = fgetc(in); ungetc(peek, in);
-               if (peek != ' ' && peek != '\t')
-                       break;
-       }
-       /* Count mbox From headers as headers */
-       if (!ofs && !memcmp(line, "From ", 5))
-               ofs = 1;
-       return ofs;
-}
-
-static unsigned hexval(int c)
-{
-       if (c >= '0' && c <= '9')
-               return c - '0';
-       if (c >= 'a' && c <= 'f')
-               return c - 'a' + 10;
-       if (c >= 'A' && c <= 'F')
-               return c - 'A' + 10;
-       return ~0;
+       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 decode_q_segment(char *in, char *ot, char *ep, int rfc2047)
+static struct strbuf *decode_q_segment(const struct strbuf *q_seg, int rfc2047)
 {
+       const char *in = q_seg->buf;
        int c;
-       while ((c = *in++) != 0 && (in <= ep)) {
+       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 */
-                       *ot++ = ((hexval(d) << 4) | hexval(*in++));
+                       strbuf_addch(out, (hexval(d) << 4) | hexval(*in++));
                        continue;
                }
                if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
                        c = 0x20;
-               *ot++ = c;
+               strbuf_addch(out, c);
        }
-       *ot = 0;
-       return 0;
+       return out;
 }
 
-static int decode_b_segment(char *in, char *ot, char *ep)
+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 && (in <= ep)) {
+       while ((c = *in++) != 0) {
                if (c == '+')
                        c = 62;
                else if (c == '/')
@@ -488,13 +323,6 @@ static int decode_b_segment(char *in, char *ot, char *ep)
                        c -= 'a' - 26;
                else if ('0' <= c && c <= '9')
                        c -= '0' - 52;
-               else if (c == '=') {
-                       /* padding is almost like (c == 0), except we do
-                        * not output NUL resulting only from it;
-                        * for now we just trust the data.
-                        */
-                       c = 0;
-               }
                else
                        continue; /* garbage */
                switch (pos++) {
@@ -502,324 +330,708 @@ static int decode_b_segment(char *in, char *ot, char *ep)
                        acc = (c << 2);
                        break;
                case 1:
-                       *ot++ = (acc | (c >> 4));
+                       strbuf_addch(out, (acc | (c >> 4)));
                        acc = (c & 15) << 4;
                        break;
                case 2:
-                       *ot++ = (acc | (c >> 2));
+                       strbuf_addch(out, (acc | (c >> 2)));
                        acc = (c & 3) << 6;
                        break;
                case 3:
-                       *ot++ = (acc | c);
+                       strbuf_addch(out, (acc | c));
                        acc = pos = 0;
                        break;
                }
        }
-       *ot = 0;
-       return 0;
+       return out;
 }
 
-static void convert_to_utf8(char *line, char *charset)
+static int convert_to_utf8(struct mailinfo *mi,
+                          struct strbuf *line, const char *charset)
 {
-#ifndef NO_ICONV
-       char *in, *out;
-       size_t insize, outsize, nrc;
-       char outbuf[4096]; /* cheat */
-       static char latin_one[] = "latin1";
-       char *input_charset = *charset ? charset : latin_one;
-       iconv_t conv = iconv_open(metainfo_charset, input_charset);
+       char *out;
 
-       if (conv == (iconv_t) -1) {
-               static int warned_latin1_once = 0;
-               if (input_charset != latin_one) {
-                       fprintf(stderr, "cannot convert from %s to %s\n",
-                               input_charset, metainfo_charset);
-                       *charset = 0;
-               }
-               else if (!warned_latin1_once) {
-                       warned_latin1_once = 1;
-                       fprintf(stderr, "tried to convert from %s to %s, "
-                               "but your iconv does not work with it.\n",
-                               input_charset, metainfo_charset);
-               }
-               return;
+       if (!mi->metainfo_charset || !charset || !*charset)
+               return 0;
+
+       if (same_encoding(mi->metainfo_charset, charset))
+               return 0;
+       out = reencode_string(line->buf, mi->metainfo_charset, charset);
+       if (!out) {
+               mi->input_error = -1;
+               return error("cannot convert from %s to %s",
+                            charset, mi->metainfo_charset);
        }
-       in = line;
-       insize = strlen(in);
-       out = outbuf;
-       outsize = sizeof(outbuf);
-       nrc = iconv(conv, &in, &insize, &out, &outsize);
-       iconv_close(conv);
-       if (nrc == (size_t) -1)
-               return;
-       *out = 0;
-       strcpy(line, outbuf);
-#endif
+       strbuf_attach(line, out, strlen(out), strlen(out));
+       return 0;
 }
 
-static void decode_header_bq(char *it)
+static void decode_header(struct mailinfo *mi, struct strbuf *it)
 {
-       char *in, *out, *ep, *cp, *sp;
-       char outbuf[1000];
+       char *in, *ep, *cp;
+       struct strbuf outbuf = STRBUF_INIT, *dec;
+       struct strbuf charset_q = STRBUF_INIT, piecebuf = STRBUF_INIT;
+       int found_error = 1; /* pessimism */
+
+       in = it->buf;
+       while (in - it->buf <= it->len && (ep = strstr(in, "=?")) != NULL) {
+               int encoding;
+               strbuf_reset(&charset_q);
+               strbuf_reset(&piecebuf);
 
-       in = it;
-       out = outbuf;
-       while ((ep = strstr(in, "=?")) != NULL) {
-               int sz, encoding;
-               char charset_q[256], piecebuf[256];
                if (in != ep) {
-                       sz = ep - in;
-                       memcpy(out, in, sz);
-                       out += sz;
-                       in += sz;
+                       /*
+                        * 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;
-               cp = strchr(ep, '?');
-               if (!cp)
-                       return; /* no munging */
-               for (sp = ep; sp < cp; sp++)
-                       charset_q[sp - ep] = tolower(*sp);
-               charset_q[cp - ep] = 0;
+
+               if (ep - it->buf >= it->len || !(cp = strchr(ep, '?')))
+                       goto release_return;
+
+               if (cp + 3 - it->buf > it->len)
+                       goto release_return;
+               strbuf_add(&charset_q, ep, cp - ep);
+
                encoding = cp[1];
                if (!encoding || cp[2] != '?')
-                       return; /* no munging */
+                       goto release_return;
                ep = strstr(cp + 3, "?=");
                if (!ep)
-                       return; /* no munging */
+                       goto release_return;
+               strbuf_add(&piecebuf, cp + 3, ep - cp - 3);
                switch (tolower(encoding)) {
                default:
-                       return; /* no munging */
+                       goto release_return;
                case 'b':
-                       sz = decode_b_segment(cp + 3, piecebuf, ep);
+                       dec = decode_b_segment(&piecebuf);
                        break;
                case 'q':
-                       sz = decode_q_segment(cp + 3, piecebuf, ep, 1);
+                       dec = decode_q_segment(&piecebuf, 1);
                        break;
                }
-               if (sz < 0)
-                       return;
-               if (metainfo_charset)
-                       convert_to_utf8(piecebuf, charset_q);
-               strcpy(out, piecebuf);
-               out += strlen(out);
+               if (convert_to_utf8(mi, dec, charset_q.buf))
+                       goto release_return;
+
+               strbuf_addbuf(&outbuf, dec);
+               strbuf_release(dec);
+               free(dec);
                in = ep + 2;
        }
-       strcpy(out, in);
-       strcpy(it, outbuf);
+       strbuf_addstr(&outbuf, in);
+       strbuf_reset(it);
+       strbuf_addbuf(it, &outbuf);
+       found_error = 0;
+release_return:
+       strbuf_release(&outbuf);
+       strbuf_release(&charset_q);
+       strbuf_release(&piecebuf);
+
+       if (found_error)
+               mi->input_error = -1;
 }
 
-static void decode_transfer_encoding(char *line)
+static int check_header(struct mailinfo *mi,
+                       const struct strbuf *line,
+                       struct strbuf *hdr_data[], int overwrite)
 {
-       char *ep;
+       int i, ret = 0, len;
+       struct strbuf sb = STRBUF_INIT;
 
-       switch (transfer_encoding) {
+       /* 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(mi, &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(mi, &sb);
+               strbuf_insert(&sb, 0, "Content-Type: ", len);
+               handle_content_type(mi, &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(mi, &sb);
+               handle_content_transfer_encoding(mi, &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(mi, &sb);
+               handle_message_id(mi, &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 void decode_transfer_encoding(struct mailinfo *mi, struct strbuf *line)
+{
+       struct strbuf *ret;
+
+       switch (mi->transfer_encoding) {
        case TE_QP:
-               ep = line + strlen(line);
-               decode_q_segment(line, line, ep, 0);
+               ret = decode_q_segment(line, 0);
                break;
        case TE_BASE64:
-               ep = line + strlen(line);
-               decode_b_segment(line, line, ep);
+               ret = decode_b_segment(line);
                break;
        case TE_DONTCARE:
-               break;
+       default:
+               return;
        }
+       strbuf_reset(line);
+       strbuf_addbuf(line, ret);
+       strbuf_release(ret);
+       free(ret);
 }
 
-static void handle_info(void)
+static inline int patchbreak(const struct strbuf *line)
 {
-       char *sub;
+       size_t i;
 
-       sub = cleanup_subject(subject);
-       cleanup_space(name);
-       cleanup_space(date);
-       cleanup_space(email);
-       cleanup_space(sub);
+       /* Beginning of a "diff -" header? */
+       if (starts_with(line->buf, "diff -"))
+               return 1;
 
-       printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
-              name, email, sub, date);
-}
+       /* CVS "Index: " line? */
+       if (starts_with(line->buf, "Index: "))
+               return 1;
 
-/* We are inside message body and have read line[] already.
- * Spit out the commit log.
- */
-static int handle_commit_msg(int *seen)
-{
-       if (!cmitmsg)
+       /*
+        * "--- <filename>" starts patches without headers
+        * "---<sp>*" is a manual separator
+        */
+       if (line->len < 4)
                return 0;
-       do {
-               if (!memcmp("diff -", line, 6) ||
-                   !memcmp("---", line, 3) ||
-                   !memcmp("Index: ", line, 7))
-                       break;
-               if ((multipart_boundary[0] && is_multipart_boundary(line))) {
-                       /* We come here when the first part had only
-                        * the commit message without any patch.  We
-                        * pretend we have not seen this line yet, and
-                        * go back to the loop.
-                        */
+
+       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;
+       }
 
-               /* Unwrap transfer encoding and optionally
-                * normalize the log message to UTF-8.
+       /*
+        * 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 mailinfo *mi, struct strbuf *line)
+{
+       assert(!mi->filter_stage);
+
+       if (mi->header_stage) {
+               if (!line->len || (line->len == 1 && line->buf[0] == '\n'))
+                       return 0;
+       }
+
+       if (mi->use_inbody_headers && mi->header_stage) {
+               mi->header_stage = check_header(mi, line, mi->s_hdr_data, 0);
+               if (mi->header_stage)
+                       return 0;
+       } else
+               /* Only trim the first (blank) line of the commit message
+                * when ignoring in-body headers.
                 */
-               decode_transfer_encoding(line);
-               if (metainfo_charset)
-                       convert_to_utf8(line, charset);
+               mi->header_stage = 0;
 
-               handle_inbody_header(seen, line);
-               if (!(*seen & SEEN_PREFIX))
-                       continue;
+       /* normalize the log message to UTF-8. */
+       if (convert_to_utf8(mi, line, mi->charset.buf))
+               return 0; /* mi->input_error already set */
 
-               fputs(line, cmitmsg);
-       } while (fgets(line, sizeof(line), stdin) != NULL);
-       fclose(cmitmsg);
-       cmitmsg = NULL;
+       if (mi->use_scissors && is_scissors_line(line)) {
+               int i;
+
+               strbuf_setlen(&mi->log_message, 0);
+               mi->header_stage = 1;
+
+               /*
+                * We may have already read "secondary headers"; purge
+                * them to give ourselves a clean restart.
+                */
+               for (i = 0; header[i]; i++) {
+                       if (mi->s_hdr_data[i])
+                               strbuf_release(mi->s_hdr_data[i]);
+                       mi->s_hdr_data[i] = NULL;
+               }
+               return 0;
+       }
+
+       if (patchbreak(line)) {
+               if (mi->message_id)
+                       strbuf_addf(&mi->log_message,
+                                   "Message-Id: %s\n", mi->message_id);
+               return 1;
+       }
+
+       strbuf_addbuf(&mi->log_message, line);
        return 0;
 }
 
-/* We have done the commit message and have the first
- * line of the patch in line[].
- */
-static void handle_patch(void)
+static void handle_patch(struct mailinfo *mi, const struct strbuf *line)
 {
-       do {
-               if (multipart_boundary[0] && is_multipart_boundary(line))
+       fwrite(line->buf, 1, line->len, mi->patchfile);
+       mi->patch_lines++;
+}
+
+static void handle_filter(struct mailinfo *mi, struct strbuf *line)
+{
+       switch (mi->filter_stage) {
+       case 0:
+               if (!handle_commit_msg(mi, line))
                        break;
-               /* Only unwrap transfer encoding but otherwise do not
-                * do anything.  We do *NOT* want UTF-8 conversion
-                * here; we are dealing with the user payload.
-                */
-               decode_transfer_encoding(line);
-               fputs(line, patchfile);
-               patch_lines++;
-       } while (fgets(line, sizeof(line), stdin) != NULL);
+               mi->filter_stage++;
+       case 1:
+               handle_patch(mi, line);
+               break;
+       }
 }
 
-/* multipart boundary and transfer encoding are set up for us, and we
- * are at the end of the sub header.  do equivalent of handle_body up
- * to the next boundary without closing patchfile --- we will expect
- * that the first part to contain commit message and a patch, and
- * handle other parts as pure patches.
- */
-static int handle_multipart_one_part(int *seen)
+static int is_rfc2822_header(const struct strbuf *line)
 {
-       int n = 0;
+       /*
+        * 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;
 
-       while (fgets(line, sizeof(line), stdin) != NULL) {
-       again:
-               n++;
-               if (is_multipart_boundary(line))
-                       break;
-               if (handle_commit_msg(seen))
-                       goto again;
-               handle_patch();
+       /* 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;
        }
-       if (n == 0)
-               return -1;
        return 0;
 }
 
-static void handle_multipart_body(void)
+static int read_one_header_line(struct strbuf *line, FILE *in)
 {
-       int seen = 0;
-       int part_num = 0;
+       struct strbuf continuation = STRBUF_INIT;
 
-       /* Skip up to the first boundary */
-       while (fgets(line, sizeof(line), stdin) != NULL)
-               if (is_multipart_boundary(line)) {
-                       part_num = 1;
-                       break;
-               }
-       if (!part_num)
-               return;
-       /* We are on boundary line.  Start slurping the subhead. */
-       while (1) {
-               int hdr = read_one_header_line(line, sizeof(line), stdin);
-               if (!hdr) {
-                       if (handle_multipart_one_part(&seen) < 0)
-                               return;
-                       /* Reset per part headers */
-                       transfer_encoding = TE_DONTCARE;
-                       charset[0] = 0;
-               }
-               else
-                       check_subheader_line(line);
+       /* 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;
        }
-       fclose(patchfile);
-       if (!patch_lines) {
-               fprintf(stderr, "No patch found\n");
-               exit(1);
+
+       /*
+        * Now we need to eat all the continuation lines..
+        * Yuck, 2822 header "folding"
+        */
+       for (;;) {
+               int peek;
+
+               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);
        }
+       strbuf_release(&continuation);
+
+       return 1;
 }
 
-/* Non multipart message */
-static void handle_body(void)
+static int find_boundary(struct mailinfo *mi, struct strbuf *line)
 {
-       int seen = 0;
+       while (!strbuf_getline(line, mi->input, '\n')) {
+               if (*(mi->content_top) && is_multipart_boundary(mi, line))
+                       return 1;
+       }
+       return 0;
+}
 
-       if (line[0] || fgets(line, sizeof(line), stdin) != NULL) {
-               handle_commit_msg(&seen);
-               handle_patch();
+static int handle_boundary(struct mailinfo *mi, struct strbuf *line)
+{
+       struct strbuf newline = STRBUF_INIT;
+
+       strbuf_addch(&newline, '\n');
+again:
+       if (line->len >= (*(mi->content_top))->len + 2 &&
+           !memcmp(line->buf + (*(mi->content_top))->len, "--", 2)) {
+               /* we hit an end boundary */
+               /* pop the current boundary off the stack */
+               strbuf_release(*(mi->content_top));
+               free(*(mi->content_top));
+               *(mi->content_top) = NULL;
+
+               /* technically won't happen as is_multipart_boundary()
+                  will fail first.  But just in case..
+                */
+               if (--mi->content_top < mi->content) {
+                       error("Detected mismatched boundaries, can't recover");
+                       mi->input_error = -1;
+                       mi->content_top = mi->content;
+                       return 0;
+               }
+               handle_filter(mi, &newline);
+               strbuf_release(&newline);
+               if (mi->input_error)
+                       return 0;
+
+               /* skip to the next boundary */
+               if (!find_boundary(mi, line))
+                       return 0;
+               goto again;
        }
-       fclose(patchfile);
-       if (!patch_lines) {
-               fprintf(stderr, "No patch found\n");
-               exit(1);
+
+       /* set some defaults */
+       mi->transfer_encoding = TE_DONTCARE;
+       strbuf_reset(&mi->charset);
+
+       /* slurp in this section's info */
+       while (read_one_header_line(line, mi->input))
+               check_header(mi, line, mi->p_hdr_data, 0);
+
+       strbuf_release(&newline);
+       /* replenish line */
+       if (strbuf_getline(line, mi->input, '\n'))
+               return 0;
+       strbuf_addch(line, '\n');
+       return 1;
+}
+
+static void handle_body(struct mailinfo *mi, struct strbuf *line)
+{
+       struct strbuf prev = STRBUF_INIT;
+
+       /* Skip up to the first boundary */
+       if (*(mi->content_top)) {
+               if (!find_boundary(mi, line))
+                       goto handle_body_out;
        }
+
+       do {
+               /* process any boundary lines */
+               if (*(mi->content_top) && is_multipart_boundary(mi, line)) {
+                       /* flush any leftover */
+                       if (prev.len) {
+                               handle_filter(mi, &prev);
+                               strbuf_reset(&prev);
+                       }
+                       if (!handle_boundary(mi, line))
+                               goto handle_body_out;
+               }
+
+               /* Unwrap transfer encoding */
+               decode_transfer_encoding(mi, line);
+
+               switch (mi->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(mi, 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(mi, line);
+               }
+
+               if (mi->input_error)
+                       break;
+       } while (!strbuf_getwholeline(line, mi->input, '\n'));
+
+handle_body_out:
+       strbuf_release(&prev);
 }
 
-static const char mailinfo_usage[] =
-       "git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";
+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;
+       }
+}
 
-int main(int argc, char **argv)
+static void handle_info(struct mailinfo *mi)
 {
-       /* NEEDSWORK: might want to do the optional .git/ directory
-        * discovery
-        */
-       git_config(git_default_config);
-
-       while (1 < argc && argv[1][0] == '-') {
-               if (!strcmp(argv[1], "-k"))
-                       keep_subject = 1;
-               else if (!strcmp(argv[1], "-u"))
-                       metainfo_charset = git_commit_encoding;
-               else if (!strncmp(argv[1], "--encoding=", 11))
-                       metainfo_charset = argv[1] + 11;
+       struct strbuf *hdr;
+       int i;
+
+       for (i = 0; header[i]; i++) {
+               /* only print inbody headers if we output a patch file */
+               if (mi->patch_lines && mi->s_hdr_data[i])
+                       hdr = mi->s_hdr_data[i];
+               else if (mi->p_hdr_data[i])
+                       hdr = mi->p_hdr_data[i];
                else
-                       usage(mailinfo_usage);
-               argc--; argv++;
+                       continue;
+
+               if (!strcmp(header[i], "Subject")) {
+                       if (!mi->keep_subject) {
+                               cleanup_subject(mi, hdr);
+                               cleanup_space(hdr);
+                       }
+                       output_header_lines(mi->output, "Subject", hdr);
+               } else if (!strcmp(header[i], "From")) {
+                       cleanup_space(hdr);
+                       handle_from(mi, hdr);
+                       fprintf(mi->output, "Author: %s\n", mi->name.buf);
+                       fprintf(mi->output, "Email: %s\n", mi->email.buf);
+               } else {
+                       cleanup_space(hdr);
+                       fprintf(mi->output, "%s: %s\n", header[i], hdr->buf);
+               }
        }
+       fprintf(mi->output, "\n");
+}
 
-       if (argc != 3)
-               usage(mailinfo_usage);
-       cmitmsg = fopen(argv[1], "w");
+int mailinfo(struct mailinfo *mi, const char *msg, const char *patch)
+{
+       FILE *cmitmsg;
+       int peek;
+       struct strbuf line = STRBUF_INIT;
+
+       cmitmsg = fopen(msg, "w");
        if (!cmitmsg) {
-               perror(argv[1]);
-               exit(1);
+               perror(msg);
+               return -1;
        }
-       patchfile = fopen(argv[2], "w");
-       if (!patchfile) {
-               perror(argv[2]);
-               exit(1);
+       mi->patchfile = fopen(patch, "w");
+       if (!mi->patchfile) {
+               perror(patch);
+               fclose(cmitmsg);
+               return -1;
        }
-       while (1) {
-               int hdr = read_one_header_line(line, sizeof(line), stdin);
-               if (!hdr) {
-                       if (multipart_boundary[0])
-                               handle_multipart_body();
-                       else
-                               handle_body();
-                       handle_info();
-                       break;
-               }
-               check_header_line(line);
+
+       mi->p_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*(mi->p_hdr_data)));
+       mi->s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*(mi->s_hdr_data)));
+
+       do {
+               peek = fgetc(mi->input);
+       } while (isspace(peek));
+       ungetc(peek, mi->input);
+
+       /* process the email header */
+       while (read_one_header_line(&line, mi->input))
+               check_header(mi, &line, mi->p_hdr_data, 1);
+
+       handle_body(mi, &line);
+       fwrite(mi->log_message.buf, 1, mi->log_message.len, cmitmsg);
+       fclose(cmitmsg);
+       fclose(mi->patchfile);
+
+       handle_info(mi);
+       strbuf_release(&line);
+       return mi->input_error;
+}
+
+static int git_mailinfo_config(const char *var, const char *value, void *mi_)
+{
+       struct mailinfo *mi = mi_;
+
+       if (!starts_with(var, "mailinfo."))
+               return git_default_config(var, value, NULL);
+       if (!strcmp(var, "mailinfo.scissors")) {
+               mi->use_scissors = git_config_bool(var, value);
+               return 0;
        }
+       /* perhaps others here */
        return 0;
 }
+
+void setup_mailinfo(struct mailinfo *mi)
+{
+       memset(mi, 0, sizeof(*mi));
+       strbuf_init(&mi->name, 0);
+       strbuf_init(&mi->email, 0);
+       strbuf_init(&mi->charset, 0);
+       strbuf_init(&mi->log_message, 0);
+       mi->header_stage = 1;
+       mi->use_inbody_headers = 1;
+       mi->content_top = mi->content;
+       git_config(git_mailinfo_config, mi);
+}
+
+void clear_mailinfo(struct mailinfo *mi)
+{
+       int i;
+
+       strbuf_release(&mi->name);
+       strbuf_release(&mi->email);
+       strbuf_release(&mi->charset);
+       free(mi->message_id);
+
+       for (i = 0; mi->p_hdr_data[i]; i++)
+               strbuf_release(mi->p_hdr_data[i]);
+       free(mi->p_hdr_data);
+       for (i = 0; mi->s_hdr_data[i]; i++)
+               strbuf_release(mi->s_hdr_data[i]);
+       free(mi->s_hdr_data);
+
+       while (mi->content < mi->content_top) {
+               free(*(mi->content_top));
+               mi->content_top--;
+       }
+
+       strbuf_release(&mi->log_message);
+}