Merge branch 'maint-1.6.3' into maint
[git] / builtin-mailinfo.c
1 /*
2  * Another stupid program, this one parsing the headers of an
3  * email to figure out authorship and subject
4  */
5 #include "cache.h"
6 #include "builtin.h"
7 #include "utf8.h"
8 #include "strbuf.h"
9
10 static FILE *cmitmsg, *patchfile, *fin, *fout;
11
12 static int keep_subject;
13 static const char *metainfo_charset;
14 static struct strbuf line = STRBUF_INIT;
15 static struct strbuf name = STRBUF_INIT;
16 static struct strbuf email = STRBUF_INIT;
17
18 static enum  {
19         TE_DONTCARE, TE_QP, TE_BASE64,
20 } transfer_encoding;
21 static enum  {
22         TYPE_TEXT, TYPE_OTHER,
23 } message_type;
24
25 static struct strbuf charset = STRBUF_INIT;
26 static int patch_lines;
27 static struct strbuf **p_hdr_data, **s_hdr_data;
28
29 #define MAX_HDR_PARSED 10
30 #define MAX_BOUNDARIES 5
31
32 static void cleanup_space(struct strbuf *sb);
33
34
35 static void get_sane_name(struct strbuf *out, struct strbuf *name, struct strbuf *email)
36 {
37         struct strbuf *src = name;
38         if (name->len < 3 || 60 < name->len || strchr(name->buf, '@') ||
39                 strchr(name->buf, '<') || strchr(name->buf, '>'))
40                 src = email;
41         else if (name == out)
42                 return;
43         strbuf_reset(out);
44         strbuf_addbuf(out, src);
45 }
46
47 static void parse_bogus_from(const struct strbuf *line)
48 {
49         /* John Doe <johndoe> */
50
51         char *bra, *ket;
52         /* This is fallback, so do not bother if we already have an
53          * e-mail address.
54          */
55         if (email.len)
56                 return;
57
58         bra = strchr(line->buf, '<');
59         if (!bra)
60                 return;
61         ket = strchr(bra, '>');
62         if (!ket)
63                 return;
64
65         strbuf_reset(&email);
66         strbuf_add(&email, bra + 1, ket - bra - 1);
67
68         strbuf_reset(&name);
69         strbuf_add(&name, line->buf, bra - line->buf);
70         strbuf_trim(&name);
71         get_sane_name(&name, &name, &email);
72 }
73
74 static void handle_from(const struct strbuf *from)
75 {
76         char *at;
77         size_t el;
78         struct strbuf f;
79
80         strbuf_init(&f, from->len);
81         strbuf_addbuf(&f, from);
82
83         at = strchr(f.buf, '@');
84         if (!at) {
85                 parse_bogus_from(from);
86                 return;
87         }
88
89         /*
90          * If we already have one email, don't take any confusing lines
91          */
92         if (email.len && strchr(at + 1, '@')) {
93                 strbuf_release(&f);
94                 return;
95         }
96
97         /* Pick up the string around '@', possibly delimited with <>
98          * pair; that is the email part.
99          */
100         while (at > f.buf) {
101                 char c = at[-1];
102                 if (isspace(c))
103                         break;
104                 if (c == '<') {
105                         at[-1] = ' ';
106                         break;
107                 }
108                 at--;
109         }
110         el = strcspn(at, " \n\t\r\v\f>");
111         strbuf_reset(&email);
112         strbuf_add(&email, at, el);
113         strbuf_remove(&f, at - f.buf, el + (at[el] ? 1 : 0));
114
115         /* The remainder is name.  It could be
116          *
117          * - "John Doe <john.doe@xz>"                   (a), or
118          * - "john.doe@xz (John Doe)"                   (b), or
119          * - "John (zzz) Doe <john.doe@xz> (Comment)"   (c)
120          *
121          * but we have removed the email part, so
122          *
123          * - remove extra spaces which could stay after email (case 'c'), and
124          * - trim from both ends, possibly removing the () pair at the end
125          *   (cases 'a' and 'b').
126          */
127         cleanup_space(&f);
128         strbuf_trim(&f);
129         if (f.buf[0] == '(' && f.len && f.buf[f.len - 1] == ')') {
130                 strbuf_remove(&f, 0, 1);
131                 strbuf_setlen(&f, f.len - 1);
132         }
133
134         get_sane_name(&name, &f, &email);
135         strbuf_release(&f);
136 }
137
138 static void handle_header(struct strbuf **out, const struct strbuf *line)
139 {
140         if (!*out) {
141                 *out = xmalloc(sizeof(struct strbuf));
142                 strbuf_init(*out, line->len);
143         } else
144                 strbuf_reset(*out);
145
146         strbuf_addbuf(*out, line);
147 }
148
149 /* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
150  * to have enough heuristics to grok MIME encoded patches often found
151  * on our mailing lists.  For example, we do not even treat header lines
152  * case insensitively.
153  */
154
155 static int slurp_attr(const char *line, const char *name, struct strbuf *attr)
156 {
157         const char *ends, *ap = strcasestr(line, name);
158         size_t sz;
159
160         if (!ap) {
161                 strbuf_setlen(attr, 0);
162                 return 0;
163         }
164         ap += strlen(name);
165         if (*ap == '"') {
166                 ap++;
167                 ends = "\"";
168         }
169         else
170                 ends = "; \t";
171         sz = strcspn(ap, ends);
172         strbuf_add(attr, ap, sz);
173         return 1;
174 }
175
176 static struct strbuf *content[MAX_BOUNDARIES];
177
178 static struct strbuf **content_top = content;
179
180 static void handle_content_type(struct strbuf *line)
181 {
182         struct strbuf *boundary = xmalloc(sizeof(struct strbuf));
183         strbuf_init(boundary, line->len);
184
185         if (!strcasestr(line->buf, "text/"))
186                  message_type = TYPE_OTHER;
187         if (slurp_attr(line->buf, "boundary=", boundary)) {
188                 strbuf_insert(boundary, 0, "--", 2);
189                 if (++content_top > &content[MAX_BOUNDARIES]) {
190                         fprintf(stderr, "Too many boundaries to handle\n");
191                         exit(1);
192                 }
193                 *content_top = boundary;
194                 boundary = NULL;
195         }
196         slurp_attr(line->buf, "charset=", &charset);
197
198         if (boundary) {
199                 strbuf_release(boundary);
200                 free(boundary);
201         }
202 }
203
204 static void handle_content_transfer_encoding(const struct strbuf *line)
205 {
206         if (strcasestr(line->buf, "base64"))
207                 transfer_encoding = TE_BASE64;
208         else if (strcasestr(line->buf, "quoted-printable"))
209                 transfer_encoding = TE_QP;
210         else
211                 transfer_encoding = TE_DONTCARE;
212 }
213
214 static int is_multipart_boundary(const struct strbuf *line)
215 {
216         return (((*content_top)->len <= line->len) &&
217                 !memcmp(line->buf, (*content_top)->buf, (*content_top)->len));
218 }
219
220 static void cleanup_subject(struct strbuf *subject)
221 {
222         char *pos;
223         size_t remove;
224         while (subject->len) {
225                 switch (*subject->buf) {
226                 case 'r': case 'R':
227                         if (subject->len <= 3)
228                                 break;
229                         if (!memcmp(subject->buf + 1, "e:", 2)) {
230                                 strbuf_remove(subject, 0, 3);
231                                 continue;
232                         }
233                         break;
234                 case ' ': case '\t': case ':':
235                         strbuf_remove(subject, 0, 1);
236                         continue;
237                 case '[':
238                         if ((pos = strchr(subject->buf, ']'))) {
239                                 remove = pos - subject->buf;
240                                 if (remove <= (subject->len - remove) * 2) {
241                                         strbuf_remove(subject, 0, remove + 1);
242                                         continue;
243                                 }
244                         } else
245                                 strbuf_remove(subject, 0, 1);
246                         break;
247                 }
248                 strbuf_trim(subject);
249                 return;
250         }
251 }
252
253 static void cleanup_space(struct strbuf *sb)
254 {
255         size_t pos, cnt;
256         for (pos = 0; pos < sb->len; pos++) {
257                 if (isspace(sb->buf[pos])) {
258                         sb->buf[pos] = ' ';
259                         for (cnt = 0; isspace(sb->buf[pos + cnt + 1]); cnt++);
260                         strbuf_remove(sb, pos + 1, cnt);
261                 }
262         }
263 }
264
265 static void decode_header(struct strbuf *line);
266 static const char *header[MAX_HDR_PARSED] = {
267         "From","Subject","Date",
268 };
269
270 static inline int cmp_header(const struct strbuf *line, const char *hdr)
271 {
272         int len = strlen(hdr);
273         return !strncasecmp(line->buf, hdr, len) && line->len > len &&
274                         line->buf[len] == ':' && isspace(line->buf[len + 1]);
275 }
276
277 static int check_header(const struct strbuf *line,
278                                 struct strbuf *hdr_data[], int overwrite)
279 {
280         int i, ret = 0, len;
281         struct strbuf sb = STRBUF_INIT;
282         /* search for the interesting parts */
283         for (i = 0; header[i]; i++) {
284                 int len = strlen(header[i]);
285                 if ((!hdr_data[i] || overwrite) && cmp_header(line, header[i])) {
286                         /* Unwrap inline B and Q encoding, and optionally
287                          * normalize the meta information to utf8.
288                          */
289                         strbuf_add(&sb, line->buf + len + 2, line->len - len - 2);
290                         decode_header(&sb);
291                         handle_header(&hdr_data[i], &sb);
292                         ret = 1;
293                         goto check_header_out;
294                 }
295         }
296
297         /* Content stuff */
298         if (cmp_header(line, "Content-Type")) {
299                 len = strlen("Content-Type: ");
300                 strbuf_add(&sb, line->buf + len, line->len - len);
301                 decode_header(&sb);
302                 strbuf_insert(&sb, 0, "Content-Type: ", len);
303                 handle_content_type(&sb);
304                 ret = 1;
305                 goto check_header_out;
306         }
307         if (cmp_header(line, "Content-Transfer-Encoding")) {
308                 len = strlen("Content-Transfer-Encoding: ");
309                 strbuf_add(&sb, line->buf + len, line->len - len);
310                 decode_header(&sb);
311                 handle_content_transfer_encoding(&sb);
312                 ret = 1;
313                 goto check_header_out;
314         }
315
316         /* for inbody stuff */
317         if (!prefixcmp(line->buf, ">From") && isspace(line->buf[5])) {
318                 ret = 1; /* Should this return 0? */
319                 goto check_header_out;
320         }
321         if (!prefixcmp(line->buf, "[PATCH]") && isspace(line->buf[7])) {
322                 for (i = 0; header[i]; i++) {
323                         if (!memcmp("Subject", header[i], 7)) {
324                                 handle_header(&hdr_data[i], line);
325                                 ret = 1;
326                                 goto check_header_out;
327                         }
328                 }
329         }
330
331 check_header_out:
332         strbuf_release(&sb);
333         return ret;
334 }
335
336 static int is_rfc2822_header(const struct strbuf *line)
337 {
338         /*
339          * The section that defines the loosest possible
340          * field name is "3.6.8 Optional fields".
341          *
342          * optional-field = field-name ":" unstructured CRLF
343          * field-name = 1*ftext
344          * ftext = %d33-57 / %59-126
345          */
346         int ch;
347         char *cp = line->buf;
348
349         /* Count mbox From headers as headers */
350         if (!prefixcmp(cp, "From ") || !prefixcmp(cp, ">From "))
351                 return 1;
352
353         while ((ch = *cp++)) {
354                 if (ch == ':')
355                         return 1;
356                 if ((33 <= ch && ch <= 57) ||
357                     (59 <= ch && ch <= 126))
358                         continue;
359                 break;
360         }
361         return 0;
362 }
363
364 static int read_one_header_line(struct strbuf *line, FILE *in)
365 {
366         /* Get the first part of the line. */
367         if (strbuf_getline(line, in, '\n'))
368                 return 0;
369
370         /*
371          * Is it an empty line or not a valid rfc2822 header?
372          * If so, stop here, and return false ("not a header")
373          */
374         strbuf_rtrim(line);
375         if (!line->len || !is_rfc2822_header(line)) {
376                 /* Re-add the newline */
377                 strbuf_addch(line, '\n');
378                 return 0;
379         }
380
381         /*
382          * Now we need to eat all the continuation lines..
383          * Yuck, 2822 header "folding"
384          */
385         for (;;) {
386                 int peek;
387                 struct strbuf continuation = STRBUF_INIT;
388
389                 peek = fgetc(in); ungetc(peek, in);
390                 if (peek != ' ' && peek != '\t')
391                         break;
392                 if (strbuf_getline(&continuation, in, '\n'))
393                         break;
394                 continuation.buf[0] = '\n';
395                 strbuf_rtrim(&continuation);
396                 strbuf_addbuf(line, &continuation);
397         }
398
399         return 1;
400 }
401
402 static struct strbuf *decode_q_segment(const struct strbuf *q_seg, int rfc2047)
403 {
404         const char *in = q_seg->buf;
405         int c;
406         struct strbuf *out = xmalloc(sizeof(struct strbuf));
407         strbuf_init(out, q_seg->len);
408
409         while ((c = *in++) != 0) {
410                 if (c == '=') {
411                         int d = *in++;
412                         if (d == '\n' || !d)
413                                 break; /* drop trailing newline */
414                         strbuf_addch(out, (hexval(d) << 4) | hexval(*in++));
415                         continue;
416                 }
417                 if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
418                         c = 0x20;
419                 strbuf_addch(out, c);
420         }
421         return out;
422 }
423
424 static struct strbuf *decode_b_segment(const struct strbuf *b_seg)
425 {
426         /* Decode in..ep, possibly in-place to ot */
427         int c, pos = 0, acc = 0;
428         const char *in = b_seg->buf;
429         struct strbuf *out = xmalloc(sizeof(struct strbuf));
430         strbuf_init(out, b_seg->len);
431
432         while ((c = *in++) != 0) {
433                 if (c == '+')
434                         c = 62;
435                 else if (c == '/')
436                         c = 63;
437                 else if ('A' <= c && c <= 'Z')
438                         c -= 'A';
439                 else if ('a' <= c && c <= 'z')
440                         c -= 'a' - 26;
441                 else if ('0' <= c && c <= '9')
442                         c -= '0' - 52;
443                 else
444                         continue; /* garbage */
445                 switch (pos++) {
446                 case 0:
447                         acc = (c << 2);
448                         break;
449                 case 1:
450                         strbuf_addch(out, (acc | (c >> 4)));
451                         acc = (c & 15) << 4;
452                         break;
453                 case 2:
454                         strbuf_addch(out, (acc | (c >> 2)));
455                         acc = (c & 3) << 6;
456                         break;
457                 case 3:
458                         strbuf_addch(out, (acc | c));
459                         acc = pos = 0;
460                         break;
461                 }
462         }
463         return out;
464 }
465
466 /*
467  * When there is no known charset, guess.
468  *
469  * Right now we assume that if the target is UTF-8 (the default),
470  * and it already looks like UTF-8 (which includes US-ASCII as its
471  * subset, of course) then that is what it is and there is nothing
472  * to do.
473  *
474  * Otherwise, we default to assuming it is Latin1 for historical
475  * reasons.
476  */
477 static const char *guess_charset(const struct strbuf *line, const char *target_charset)
478 {
479         if (is_encoding_utf8(target_charset)) {
480                 if (is_utf8(line->buf))
481                         return NULL;
482         }
483         return "ISO8859-1";
484 }
485
486 static void convert_to_utf8(struct strbuf *line, const char *charset)
487 {
488         char *out;
489
490         if (!charset || !*charset) {
491                 charset = guess_charset(line, metainfo_charset);
492                 if (!charset)
493                         return;
494         }
495
496         if (!strcasecmp(metainfo_charset, charset))
497                 return;
498         out = reencode_string(line->buf, metainfo_charset, charset);
499         if (!out)
500                 die("cannot convert from %s to %s",
501                     charset, metainfo_charset);
502         strbuf_attach(line, out, strlen(out), strlen(out));
503 }
504
505 static int decode_header_bq(struct strbuf *it)
506 {
507         char *in, *ep, *cp;
508         struct strbuf outbuf = STRBUF_INIT, *dec;
509         struct strbuf charset_q = STRBUF_INIT, piecebuf = STRBUF_INIT;
510         int rfc2047 = 0;
511
512         in = it->buf;
513         while (in - it->buf <= it->len && (ep = strstr(in, "=?")) != NULL) {
514                 int encoding;
515                 strbuf_reset(&charset_q);
516                 strbuf_reset(&piecebuf);
517                 rfc2047 = 1;
518
519                 if (in != ep) {
520                         /*
521                          * We are about to process an encoded-word
522                          * that begins at ep, but there is something
523                          * before the encoded word.
524                          */
525                         char *scan;
526                         for (scan = in; scan < ep; scan++)
527                                 if (!isspace(*scan))
528                                         break;
529
530                         if (scan != ep || in == it->buf) {
531                                 /*
532                                  * We should not lose that "something",
533                                  * unless we have just processed an
534                                  * encoded-word, and there is only LWS
535                                  * before the one we are about to process.
536                                  */
537                                 strbuf_add(&outbuf, in, ep - in);
538                         }
539                 }
540                 /* E.g.
541                  * ep : "=?iso-2022-jp?B?GyR...?= foo"
542                  * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
543                  */
544                 ep += 2;
545
546                 if (ep - it->buf >= it->len || !(cp = strchr(ep, '?')))
547                         goto decode_header_bq_out;
548
549                 if (cp + 3 - it->buf > it->len)
550                         goto decode_header_bq_out;
551                 strbuf_add(&charset_q, ep, cp - ep);
552
553                 encoding = cp[1];
554                 if (!encoding || cp[2] != '?')
555                         goto decode_header_bq_out;
556                 ep = strstr(cp + 3, "?=");
557                 if (!ep)
558                         goto decode_header_bq_out;
559                 strbuf_add(&piecebuf, cp + 3, ep - cp - 3);
560                 switch (tolower(encoding)) {
561                 default:
562                         goto decode_header_bq_out;
563                 case 'b':
564                         dec = decode_b_segment(&piecebuf);
565                         break;
566                 case 'q':
567                         dec = decode_q_segment(&piecebuf, 1);
568                         break;
569                 }
570                 if (metainfo_charset)
571                         convert_to_utf8(dec, charset_q.buf);
572
573                 strbuf_addbuf(&outbuf, dec);
574                 strbuf_release(dec);
575                 free(dec);
576                 in = ep + 2;
577         }
578         strbuf_addstr(&outbuf, in);
579         strbuf_reset(it);
580         strbuf_addbuf(it, &outbuf);
581 decode_header_bq_out:
582         strbuf_release(&outbuf);
583         strbuf_release(&charset_q);
584         strbuf_release(&piecebuf);
585         return rfc2047;
586 }
587
588 static void decode_header(struct strbuf *it)
589 {
590         if (decode_header_bq(it))
591                 return;
592         /* otherwise "it" is a straight copy of the input.
593          * This can be binary guck but there is no charset specified.
594          */
595         if (metainfo_charset)
596                 convert_to_utf8(it, "");
597 }
598
599 static void decode_transfer_encoding(struct strbuf *line)
600 {
601         struct strbuf *ret;
602
603         switch (transfer_encoding) {
604         case TE_QP:
605                 ret = decode_q_segment(line, 0);
606                 break;
607         case TE_BASE64:
608                 ret = decode_b_segment(line);
609                 break;
610         case TE_DONTCARE:
611         default:
612                 return;
613         }
614         strbuf_reset(line);
615         strbuf_addbuf(line, ret);
616         strbuf_release(ret);
617         free(ret);
618 }
619
620 static void handle_filter(struct strbuf *line);
621
622 static int find_boundary(void)
623 {
624         while (!strbuf_getline(&line, fin, '\n')) {
625                 if (*content_top && is_multipart_boundary(&line))
626                         return 1;
627         }
628         return 0;
629 }
630
631 static int handle_boundary(void)
632 {
633         struct strbuf newline = STRBUF_INIT;
634
635         strbuf_addch(&newline, '\n');
636 again:
637         if (line.len >= (*content_top)->len + 2 &&
638             !memcmp(line.buf + (*content_top)->len, "--", 2)) {
639                 /* we hit an end boundary */
640                 /* pop the current boundary off the stack */
641                 strbuf_release(*content_top);
642                 free(*content_top);
643                 *content_top = NULL;
644
645                 /* technically won't happen as is_multipart_boundary()
646                    will fail first.  But just in case..
647                  */
648                 if (--content_top < content) {
649                         fprintf(stderr, "Detected mismatched boundaries, "
650                                         "can't recover\n");
651                         exit(1);
652                 }
653                 handle_filter(&newline);
654                 strbuf_release(&newline);
655
656                 /* skip to the next boundary */
657                 if (!find_boundary())
658                         return 0;
659                 goto again;
660         }
661
662         /* set some defaults */
663         transfer_encoding = TE_DONTCARE;
664         strbuf_reset(&charset);
665         message_type = TYPE_TEXT;
666
667         /* slurp in this section's info */
668         while (read_one_header_line(&line, fin))
669                 check_header(&line, p_hdr_data, 0);
670
671         strbuf_release(&newline);
672         /* replenish line */
673         if (strbuf_getline(&line, fin, '\n'))
674                 return 0;
675         strbuf_addch(&line, '\n');
676         return 1;
677 }
678
679 static inline int patchbreak(const struct strbuf *line)
680 {
681         size_t i;
682
683         /* Beginning of a "diff -" header? */
684         if (!prefixcmp(line->buf, "diff -"))
685                 return 1;
686
687         /* CVS "Index: " line? */
688         if (!prefixcmp(line->buf, "Index: "))
689                 return 1;
690
691         /*
692          * "--- <filename>" starts patches without headers
693          * "---<sp>*" is a manual separator
694          */
695         if (line->len < 4)
696                 return 0;
697
698         if (!prefixcmp(line->buf, "---")) {
699                 /* space followed by a filename? */
700                 if (line->buf[3] == ' ' && !isspace(line->buf[4]))
701                         return 1;
702                 /* Just whitespace? */
703                 for (i = 3; i < line->len; i++) {
704                         unsigned char c = line->buf[i];
705                         if (c == '\n')
706                                 return 1;
707                         if (!isspace(c))
708                                 break;
709                 }
710                 return 0;
711         }
712         return 0;
713 }
714
715 static int handle_commit_msg(struct strbuf *line)
716 {
717         static int still_looking = 1;
718
719         if (!cmitmsg)
720                 return 0;
721
722         if (still_looking) {
723                 strbuf_ltrim(line);
724                 if (!line->len)
725                         return 0;
726                 if ((still_looking = check_header(line, s_hdr_data, 0)) != 0)
727                         return 0;
728         }
729
730         /* normalize the log message to UTF-8. */
731         if (metainfo_charset)
732                 convert_to_utf8(line, charset.buf);
733
734         if (patchbreak(line)) {
735                 fclose(cmitmsg);
736                 cmitmsg = NULL;
737                 return 1;
738         }
739
740         fputs(line->buf, cmitmsg);
741         return 0;
742 }
743
744 static void handle_patch(const struct strbuf *line)
745 {
746         fwrite(line->buf, 1, line->len, patchfile);
747         patch_lines++;
748 }
749
750 static void handle_filter(struct strbuf *line)
751 {
752         static int filter = 0;
753
754         /* filter tells us which part we left off on */
755         switch (filter) {
756         case 0:
757                 if (!handle_commit_msg(line))
758                         break;
759                 filter++;
760         case 1:
761                 handle_patch(line);
762                 break;
763         }
764 }
765
766 static void handle_body(void)
767 {
768         int len = 0;
769         struct strbuf prev = STRBUF_INIT;
770
771         /* Skip up to the first boundary */
772         if (*content_top) {
773                 if (!find_boundary())
774                         goto handle_body_out;
775         }
776
777         do {
778                 strbuf_setlen(&line, line.len + len);
779
780                 /* process any boundary lines */
781                 if (*content_top && is_multipart_boundary(&line)) {
782                         /* flush any leftover */
783                         if (prev.len) {
784                                 handle_filter(&prev);
785                                 strbuf_reset(&prev);
786                         }
787                         if (!handle_boundary())
788                                 goto handle_body_out;
789                 }
790
791                 /* Unwrap transfer encoding */
792                 decode_transfer_encoding(&line);
793
794                 switch (transfer_encoding) {
795                 case TE_BASE64:
796                 case TE_QP:
797                 {
798                         struct strbuf **lines, **it, *sb;
799
800                         /* Prepend any previous partial lines */
801                         strbuf_insert(&line, 0, prev.buf, prev.len);
802                         strbuf_reset(&prev);
803
804                         /* binary data most likely doesn't have newlines */
805                         if (message_type != TYPE_TEXT) {
806                                 handle_filter(&line);
807                                 break;
808                         }
809                         /*
810                          * This is a decoded line that may contain
811                          * multiple new lines.  Pass only one chunk
812                          * at a time to handle_filter()
813                          */
814                         lines = strbuf_split(&line, '\n');
815                         for (it = lines; (sb = *it); it++) {
816                                 if (*(it + 1) == NULL) /* The last line */
817                                         if (sb->buf[sb->len - 1] != '\n') {
818                                                 /* Partial line, save it for later. */
819                                                 strbuf_addbuf(&prev, sb);
820                                                 break;
821                                         }
822                                 handle_filter(sb);
823                         }
824                         /*
825                          * The partial chunk is saved in "prev" and will be
826                          * appended by the next iteration of read_line_with_nul().
827                          */
828                         strbuf_list_free(lines);
829                         break;
830                 }
831                 default:
832                         handle_filter(&line);
833                 }
834
835                 strbuf_reset(&line);
836                 if (strbuf_avail(&line) < 100)
837                         strbuf_grow(&line, 100);
838         } while ((len = read_line_with_nul(line.buf, strbuf_avail(&line), fin)));
839
840 handle_body_out:
841         strbuf_release(&prev);
842 }
843
844 static void output_header_lines(FILE *fout, const char *hdr, const struct strbuf *data)
845 {
846         const char *sp = data->buf;
847         while (1) {
848                 char *ep = strchr(sp, '\n');
849                 int len;
850                 if (!ep)
851                         len = strlen(sp);
852                 else
853                         len = ep - sp;
854                 fprintf(fout, "%s: %.*s\n", hdr, len, sp);
855                 if (!ep)
856                         break;
857                 sp = ep + 1;
858         }
859 }
860
861 static void handle_info(void)
862 {
863         struct strbuf *hdr;
864         int i;
865
866         for (i = 0; header[i]; i++) {
867                 /* only print inbody headers if we output a patch file */
868                 if (patch_lines && s_hdr_data[i])
869                         hdr = s_hdr_data[i];
870                 else if (p_hdr_data[i])
871                         hdr = p_hdr_data[i];
872                 else
873                         continue;
874
875                 if (!memcmp(header[i], "Subject", 7)) {
876                         if (!keep_subject) {
877                                 cleanup_subject(hdr);
878                                 cleanup_space(hdr);
879                         }
880                         output_header_lines(fout, "Subject", hdr);
881                 } else if (!memcmp(header[i], "From", 4)) {
882                         cleanup_space(hdr);
883                         handle_from(hdr);
884                         fprintf(fout, "Author: %s\n", name.buf);
885                         fprintf(fout, "Email: %s\n", email.buf);
886                 } else {
887                         cleanup_space(hdr);
888                         fprintf(fout, "%s: %s\n", header[i], hdr->buf);
889                 }
890         }
891         fprintf(fout, "\n");
892 }
893
894 static int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,
895                     const char *msg, const char *patch)
896 {
897         int peek;
898         keep_subject = ks;
899         metainfo_charset = encoding;
900         fin = in;
901         fout = out;
902
903         cmitmsg = fopen(msg, "w");
904         if (!cmitmsg) {
905                 perror(msg);
906                 return -1;
907         }
908         patchfile = fopen(patch, "w");
909         if (!patchfile) {
910                 perror(patch);
911                 fclose(cmitmsg);
912                 return -1;
913         }
914
915         p_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*p_hdr_data));
916         s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*s_hdr_data));
917
918         do {
919                 peek = fgetc(in);
920         } while (isspace(peek));
921         ungetc(peek, in);
922
923         /* process the email header */
924         while (read_one_header_line(&line, fin))
925                 check_header(&line, p_hdr_data, 1);
926
927         handle_body();
928         handle_info();
929
930         return 0;
931 }
932
933 static const char mailinfo_usage[] =
934         "git mailinfo [-k] [-u | --encoding=<encoding> | -n] msg patch <mail >info";
935
936 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
937 {
938         const char *def_charset;
939
940         /* NEEDSWORK: might want to do the optional .git/ directory
941          * discovery
942          */
943         git_config(git_default_config, NULL);
944
945         def_charset = (git_commit_encoding ? git_commit_encoding : "UTF-8");
946         metainfo_charset = def_charset;
947
948         while (1 < argc && argv[1][0] == '-') {
949                 if (!strcmp(argv[1], "-k"))
950                         keep_subject = 1;
951                 else if (!strcmp(argv[1], "-u"))
952                         metainfo_charset = def_charset;
953                 else if (!strcmp(argv[1], "-n"))
954                         metainfo_charset = NULL;
955                 else if (!prefixcmp(argv[1], "--encoding="))
956                         metainfo_charset = argv[1] + 11;
957                 else
958                         usage(mailinfo_usage);
959                 argc--; argv++;
960         }
961
962         if (argc != 3)
963                 usage(mailinfo_usage);
964
965         return !!mailinfo(stdin, stdout, keep_subject, metainfo_charset, argv[1], argv[2]);
966 }