[thirdparty/git.git] / mailinfo.c

/*
 * 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>
#include <iconv.h>
#include "git-compat-util.h"
#include "cache.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 char *sanity_check(char *name, char *email)
{
	int len = strlen(name);
	if (len < 3 || len > 60)
		return email;
	if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
		return email;
	return name;
}

static int bogus_from(char *line)
{
	/* John Doe <johndoe> */
	char *bra, *ket, *dst, *cp;

	/* This is fallback, so do not bother if we already have an
	 * e-mail address.
	 */ 
	if (*email)
		return 0;

	bra = strchr(line, '<');
	if (!bra)
		return 0;
	ket = strchr(bra, '>');
	if (!ket)
		return 0;

	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;
}

static int handle_from(char *line)
{
	char *at = strchr(line, '@');
	char *dst;

	if (!at)
		return bogus_from(line);

	/*
	 * If we already have one email, don't take any confusing lines
	 */
	if (*email && strchr(at+1, '@'))
		return 0;

	/* Pick up the string around '@', possibly delimited with <>
	 * pair; that is the email part.  White them out while copying.
	 */
	while (at > line) {
		char c = at[-1];
		if (isspace(c))
			break;
		if (c == '<') {
			at[-1] = ' ';
			break;
		}
		at--;
	}
	dst = email;
	for (;;) {
		unsigned char c = *at;
		if (!c || c == '>' || isspace(c)) {
			if (c == '>')
				*at = ' ';
			break;
		}
		*at++ = ' ';
		*dst++ = c;
	}
	*dst++ = 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.
	 */
	at = line + strlen(line);
	while (at > line) {
		unsigned char c = *--at;
		if (!isspace(c)) {
			at[(c == ')') ? 0 : 1] = 0;
			break;
		}
	}

	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;
}

static int handle_date(char *line)
{
	strcpy(date, line);
	return 0;
}

static int handle_subject(char *line)
{
	strcpy(subject, line);
	return 0;
}

/* 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, char *attr)
{
	char *ends, *ap = strcasestr(line, name);
	size_t sz;

	if (!ap) {
		*attr = 0;
		return 0;
	}
	ap += strlen(name);
	if (*ap == '"') {
		ap++;
		ends = "\"";
	}
	else
		ends = "; \t";
	sz = strcspn(ap, ends);
	memcpy(attr, ap, sz);
	attr[sz] = 0;
	return 1;
}

static int handle_subcontent_type(char *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);
	}
	slurp_attr(line, "charset=", charset);
	if (*charset) {
		int i, c;
		for (i = 0; (c = charset[i]) != 0; i++)
			charset[i] = tolower(c);
	}
	return 0;
}

static int handle_content_type(char *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;
}

static int handle_content_transfer_encoding(char *line)
{
	if (strcasestr(line, "base64"))
		transfer_encoding = TE_BASE64;
	else if (strcasestr(line, "quoted-printable"))
		transfer_encoding = TE_QP;
	else
		transfer_encoding = TE_DONTCARE;
	return 0;
}

static int is_multipart_boundary(const char *line)
{
	return (!memcmp(line, multipart_boundary, multipart_boundary_len));
}

static int eatspace(char *line)
{
	int len = strlen(line);
	while (len > 0 && isspace(line[len-1]))
		line[--len] = 0;
	return len;
}

#define SEEN_FROM 01
#define SEEN_DATE 02
#define SEEN_SUBJECT 04

/* First lines of body can have From:, Date:, and Subject: */
static int handle_inbody_header(int *seen, char *line)
{
	if (!memcmp("From:", line, 5) && isspace(line[5])) {
		if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
			*seen |= SEEN_FROM;
			return 1;
		}
	}
	if (!memcmp("Date:", line, 5) && isspace(line[5])) {
		if (!(*seen & SEEN_DATE)) {
			handle_date(line+6);
			*seen |= SEEN_DATE;
			return 1;
		}
	}
	if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
		if (!(*seen & SEEN_SUBJECT)) {
			handle_subject(line+9);
			*seen |= SEEN_SUBJECT;
			return 1;
		}
	}
	if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
		if (!(*seen & SEEN_SUBJECT)) {
			handle_subject(line);
			*seen |= SEEN_SUBJECT;
			return 1;
		}
	}
	return 0;
}

static char *cleanup_subject(char *subject)
{
	if (keep_subject)
		return subject;
	for (;;) {
		char *p;
		int len, remove;
		switch (*subject) {
		case 'r': case 'R':
			if (!memcmp("e:", subject+1, 2)) {
				subject +=3;
				continue;
			}
			break;
		case ' ': case '\t': case ':':
			subject++;
			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;
			}
		}
	}
}

typedef int (*header_fn_t)(char *);
struct header_def {
	const char *name;
	header_fn_t func;
	int namelen;
};

static void check_header(char *line, int len, struct header_def *header)
{
	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])) {
			header[i].func(line + len + 2);
			break;
		}
	}
}

static void check_subheader_line(char *line, int len)
{
	static struct header_def header[] = {
		{ "Content-Type", handle_subcontent_type },
		{ "Content-Transfer-Encoding",
		  handle_content_transfer_encoding },
		{ NULL },
	};
	check_header(line, len, header);
}
static void check_header_line(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, len, header);
}

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)
			return ofs;
		len = eatspace(line + ofs);
		if (len == 0)
			return ofs;
		peek = fgetc(in); ungetc(peek, in);
		if (peek == ' ' || peek == '\t') {
			/* Yuck, 2822 header "folding" */
			ofs += len;
			continue;
		}
		return ofs + len;
	}
	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;
}

static int decode_q_segment(char *in, char *ot, char *ep)
{
	int c;
	while ((c = *in++) != 0 && (in <= ep)) {
		if (c == '=') {
			int d = *in++;
			if (d == '\n' || !d)
				break; /* drop trailing newline */
			*ot++ = ((hexval(d) << 4) | hexval(*in++));
		}
		else
			*ot++ = c;
	}
	*ot = 0;
	return 0;
}

static int decode_b_segment(char *in, char *ot, char *ep)
{
	/* Decode in..ep, possibly in-place to ot */
	int c, pos = 0, acc = 0;

	while ((c = *in++) != 0 && (in <= ep)) {
		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 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++) {
		case 0:
			acc = (c << 2);
			break;
		case 1:
			*ot++ = (acc | (c >> 4));
			acc = (c & 15) << 4;
			break;
		case 2:
			*ot++ = (acc | (c >> 2));
			acc = (c & 3) << 6;
			break;
		case 3:
			*ot++ = (acc | c);
			acc = pos = 0;
			break;
		}
	}
	*ot = 0;
	return 0;
}

static void convert_to_utf8(char *line, char *charset)
{
	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);

	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;
	}
	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);
}

static void decode_header_bq(char *it)
{
	char *in, *out, *ep, *cp, *sp;
	char outbuf[1000];

	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;
		}
		/* 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;
		encoding = cp[1];
		if (!encoding || cp[2] != '?')
			return; /* no munging */
		ep = strstr(cp + 3, "?=");
		if (!ep)
			return; /* no munging */
		switch (tolower(encoding)) {
		default:
			return; /* no munging */
		case 'b':
			sz = decode_b_segment(cp + 3, piecebuf, ep);
			break;
		case 'q':
			sz = decode_q_segment(cp + 3, piecebuf, ep);
			break;
		}
		if (sz < 0)
			return;
		if (metainfo_charset)
			convert_to_utf8(piecebuf, charset_q);
		strcpy(out, piecebuf);
		out += strlen(out);
		in = ep + 2;
	}
	strcpy(out, in);
	strcpy(it, outbuf);
}

static void decode_transfer_encoding(char *line)
{
	char *ep;

	switch (transfer_encoding) {
	case TE_QP:
		ep = line + strlen(line);
		decode_q_segment(line, line, ep);
		break;
	case TE_BASE64:
		ep = line + strlen(line);
		decode_b_segment(line, line, ep);
		break;
	case TE_DONTCARE:
		break;
	}
}

static void handle_info(void)
{
	char *sub;
	static int done_info = 0;

	if (done_info)
		return;

	done_info = 1;
	sub = cleanup_subject(subject);
	cleanup_space(name);
	cleanup_space(date);
	cleanup_space(email);
	cleanup_space(sub);

	/* Unwrap inline B and Q encoding, and optionally
	 * normalize the meta information to utf8.
	 */
	decode_header_bq(name);
	decode_header_bq(date);
	decode_header_bq(email);
	decode_header_bq(sub);
	printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
	       name, email, sub, date);
}

/* We are inside message body and have read line[] already.
 * Spit out the commit log.
 */
static int handle_commit_msg(void)
{
	if (!cmitmsg)
		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.
			 */
			return 1;
		}

		/* Unwrap transfer encoding and optionally
		 * normalize the log message to UTF-8.
		 */
		decode_transfer_encoding(line);
		if (metainfo_charset)
			convert_to_utf8(line, charset);
		fputs(line, cmitmsg);
	} while (fgets(line, sizeof(line), stdin) != NULL);
	fclose(cmitmsg);
	cmitmsg = NULL;
	return 0;
}

/* We have done the commit message and have the first
 * line of the patch in line[].
 */
static void handle_patch(void)
{
	do {
		if (multipart_boundary[0] && is_multipart_boundary(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);
}

/* 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(void)
{
	int seen = 0;
	int n = 0;
	int len;

	while (fgets(line, sizeof(line), stdin) != NULL) {
	again:
		len = eatspace(line);
		n++;
		if (!len)
			continue;
		if (is_multipart_boundary(line))
			break;
		if (0 <= seen && handle_inbody_header(&seen, line))
			continue;
		seen = -1; /* no more inbody headers */
		line[len] = '\n';
		handle_info();
		if (handle_commit_msg())
			goto again;
		handle_patch();
		break;
	}
	if (n == 0)
		return -1;
	return 0;
}

static void handle_multipart_body(void)
{
	int part_num = 0;

	/* 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 len = read_one_header_line(line, sizeof(line), stdin);
		if (!len) {
			if (handle_multipart_one_part() < 0)
				return;
		}
		else
			check_subheader_line(line, len);
	}
	fclose(patchfile);
	if (!patch_lines) {
		fprintf(stderr, "No patch found\n");
		exit(1);
	}
}

/* Non multipart message */
static void handle_body(void)
{
	int seen = 0;

	while (fgets(line, sizeof(line), stdin) != NULL) {
		int len = eatspace(line);
		if (!len)
			continue;
		if (0 <= seen && handle_inbody_header(&seen, line))
			continue;
		seen = -1; /* no more inbody headers */
		line[len] = '\n';
		handle_info();
		handle_commit_msg();
		handle_patch();
		break;
	}
	fclose(patchfile);
	if (!patch_lines) {
		fprintf(stderr, "No patch found\n");
		exit(1);
	}
}

static const char mailinfo_usage[] =
	"git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";

int main(int argc, char **argv)
{
	/* 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;
		else
			usage(mailinfo_usage);
		argc--; argv++;
	}

	if (argc != 3)
		usage(mailinfo_usage);
	cmitmsg = fopen(argv[1], "w");
	if (!cmitmsg) {
		perror(argv[1]);
		exit(1);
	}
	patchfile = fopen(argv[2], "w");
	if (!patchfile) {
		perror(argv[2]);
		exit(1);
	}
	while (1) {
		int len = read_one_header_line(line, sizeof(line), stdin);
		if (!len) {
			if (multipart_boundary[0])
				handle_multipart_body();
			else
				handle_body();
			break;
		}
		check_header_line(line, len);
	}
	return 0;
}
Commit	Line	Data
2744b234 LT	1	/*
	2	* Another stupid program, this one parsing the headers of an
	3	* email to figure out authorship and subject
	4	*/
d4a9ce78	5	#define _GNU_SOURCE
2744b234 LT	6	#include <stdio.h>
	7	#include <stdlib.h>
	8	#include <string.h>
	9	#include <ctype.h>
d4a9ce78	10	#include <iconv.h>
a6da9395	11	#include "git-compat-util.h"
f1f909e3	12	#include "cache.h"
2744b234	13
a196d8d4	14	static FILE cmitmsg, patchfile;
2744b234	15
6bff6a60	16	static int keep_subject = 0;
650e4be5	17	static char *metainfo_charset = NULL;
2744b234	18	static char line[1000];
62c1f6b4	19	static char date[1000];
2744b234 LT	20	static char name[1000];
	21	static char email[1000];
	22	static char subject[1000];
	23
d4a9ce78 JH	24	static enum {
	25	TE_DONTCARE, TE_QP, TE_BASE64,
	26	} transfer_encoding;
	27	static char charset[256];
	28
	29	static char multipart_boundary[1000];
	30	static int multipart_boundary_len;
	31	static int patch_lines = 0;
	32
2744b234 LT	33	static char sanity_check(char name, char *email)
	34	{
	35	int len = strlen(name);
	36	if (len < 3 \|\| len > 60)
	37	return email;
	38	if (strchr(name, '@') \|\| strchr(name, '<') \|\| strchr(name, '>'))
	39	return email;
	40	return name;
	41	}
	42
e0e3ba20 JH	43	static int bogus_from(char *line)
	44	{
	45	/* John Doe <johndoe> */
	46	char bra, ket, dst, cp;
	47
	48	/* This is fallback, so do not bother if we already have an
	49	* e-mail address.
	50	*/
	51	if (*email)
	52	return 0;
	53
	54	bra = strchr(line, '<');
	55	if (!bra)
	56	return 0;
	57	ket = strchr(bra, '>');
	58	if (!ket)
	59	return 0;
	60
	61	for (dst = email, cp = bra+1; cp < ket; )
	62	dst++ = cp++;
	63	*dst = 0;
	64	for (cp = line; isspace(*cp); cp++)
	65	;
	66	for (bra--; isspace(*bra); bra--)
	67	*bra = 0;
	68	cp = sanity_check(cp, email);
	69	strcpy(name, cp);
	70	return 1;
	71	}
	72
2744b234 LT	73	static int handle_from(char *line)
	74	{
	75	char *at = strchr(line, '@');
	76	char *dst;
	77
	78	if (!at)
e0e3ba20	79	return bogus_from(line);
2744b234 LT	80
	81	/*
	82	* If we already have one email, don't take any confusing lines
	83	*/
	84	if (*email && strchr(at+1, '@'))
	85	return 0;
	86
d4a9ce78 JH	87	/* Pick up the string around '@', possibly delimited with <>
	88	* pair; that is the email part. White them out while copying.
	89	*/
2744b234 LT	90	while (at > line) {
2744b234 LT	91	char c = at[-1];
d4a9ce78 JH	92	if (isspace(c))
	93	break;
	94	if (c == '<') {
	95	at[-1] = ' ';
2744b234	96	break;
d4a9ce78	97	}
2744b234 LT	98	at--;
	99	}
	100	dst = email;
	101	for (;;) {
	102	unsigned char c = *at;
d4a9ce78 JH	103	if (!c \|\| c == '>' \|\| isspace(c)) {
	104	if (c == '>')
	105	*at = ' ';
2744b234	106	break;
d4a9ce78	107	}
2744b234 LT	108	*at++ = ' ';
	109	*dst++ = c;
	110	}
	111	*dst++ = 0;
	112
d4a9ce78 JH	113	/* The remainder is name. It could be "John Doe <john.doe@xz>"
	114	* or "john.doe@xz (John Doe)", but we have whited out the
	115	* email part, so trim from both ends, possibly removing
	116	* the () pair at the end.
	117	*/
2744b234 LT	118	at = line + strlen(line);
	119	while (at > line) {
	120	unsigned char c = *--at;
d4a9ce78 JH	121	if (!isspace(c)) {
d4a9ce78 JH	122	at[(c == ')') ? 0 : 1] = 0;
2744b234	123	break;
d4a9ce78	124	}
2744b234 LT	125	}
	126
	127	at = line;
	128	for (;;) {
	129	unsigned char c = *at;
d4a9ce78 JH	130	if (!c \|\| !isspace(c)) {
	131	if (c == '(')
	132	at++;
2744b234	133	break;
d4a9ce78	134	}
2744b234 LT	135	at++;
2744b234 LT	136	}
2744b234	137	at = sanity_check(at, email);
2744b234 LT	138	strcpy(name, at);
	139	return 1;
	140	}
	141
d4a9ce78	142	static int handle_date(char *line)
62c1f6b4 LT	143	{
62c1f6b4 LT	144	strcpy(date, line);
d4a9ce78	145	return 0;
62c1f6b4 LT	146	}
62c1f6b4 LT	147
d4a9ce78	148	static int handle_subject(char *line)
2744b234 LT	149	{
2744b234 LT	150	strcpy(subject, line);
d4a9ce78 JH	151	return 0;
	152	}
	153
	154	/* NOTE NOTE NOTE. We do not claim we do full MIME. We just attempt
	155	* to have enough heuristics to grok MIME encoded patches often found
	156	* on our mailing lists. For example, we do not even treat header lines
	157	* case insensitively.
	158	*/
	159
	160	static int slurp_attr(const char line, const char name, char *attr)
	161	{
	162	char ends, ap = strcasestr(line, name);
	163	size_t sz;
	164
	165	if (!ap) {
	166	*attr = 0;
	167	return 0;
	168	}
	169	ap += strlen(name);
	170	if (*ap == '"') {
	171	ap++;
	172	ends = "\"";
	173	}
	174	else
	175	ends = "; \t";
	176	sz = strcspn(ap, ends);
	177	memcpy(attr, ap, sz);
	178	attr[sz] = 0;
	179	return 1;
	180	}
	181
	182	static int handle_subcontent_type(char *line)
	183	{
	184	/* We do not want to mess with boundary. Note that we do not
	185	* handle nested multipart.
	186	*/
b893f091 JH	187	if (strcasestr(line, "boundary=")) {
	188	fprintf(stderr, "Not handling nested multipart message.\n");
	189	exit(1);
	190	}
d4a9ce78 JH	191	slurp_attr(line, "charset=", charset);
	192	if (*charset) {
	193	int i, c;
	194	for (i = 0; (c = charset[i]) != 0; i++)
	195	charset[i] = tolower(c);
	196	}
	197	return 0;
	198	}
	199
	200	static int handle_content_type(char *line)
	201	{
	202	*multipart_boundary = 0;
	203	if (slurp_attr(line, "boundary=", multipart_boundary + 2)) {
	204	memcpy(multipart_boundary, "--", 2);
	205	multipart_boundary_len = strlen(multipart_boundary);
	206	}
	207	slurp_attr(line, "charset=", charset);
	208	return 0;
	209	}
	210
	211	static int handle_content_transfer_encoding(char *line)
	212	{
	213	if (strcasestr(line, "base64"))
	214	transfer_encoding = TE_BASE64;
	215	else if (strcasestr(line, "quoted-printable"))
	216	transfer_encoding = TE_QP;
	217	else
	218	transfer_encoding = TE_DONTCARE;
	219	return 0;
2744b234 LT	220	}
2744b234 LT	221
d4a9ce78 JH	222	static int is_multipart_boundary(const char *line)
	223	{
	224	return (!memcmp(line, multipart_boundary, multipart_boundary_len));
	225	}
	226
	227	static int eatspace(char *line)
2744b234	228	{
d4a9ce78 JH	229	int len = strlen(line);
	230	while (len > 0 && isspace(line[len-1]))
	231	line[--len] = 0;
	232	return len;
2744b234 LT	233	}
2744b234 LT	234
d4a9ce78 JH	235	#define SEEN_FROM 01
	236	#define SEEN_DATE 02
	237	#define SEEN_SUBJECT 04
	238
	239	/* First lines of body can have From:, Date:, and Subject: */
	240	static int handle_inbody_header(int seen, char line)
	241	{
	242	if (!memcmp("From:", line, 5) && isspace(line[5])) {
	243	if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
	244	*seen \|= SEEN_FROM;
	245	return 1;
	246	}
	247	}
	248	if (!memcmp("Date:", line, 5) && isspace(line[5])) {
	249	if (!(*seen & SEEN_DATE)) {
	250	handle_date(line+6);
	251	*seen \|= SEEN_DATE;
	252	return 1;
	253	}
	254	}
	255	if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
	256	if (!(*seen & SEEN_SUBJECT)) {
	257	handle_subject(line+9);
	258	*seen \|= SEEN_SUBJECT;
	259	return 1;
	260	}
	261	}
	262	if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
	263	if (!(*seen & SEEN_SUBJECT)) {
	264	handle_subject(line);
	265	*seen \|= SEEN_SUBJECT;
	266	return 1;
	267	}
	268	}
	269	return 0;
	270	}
	271
	272	static char cleanup_subject(char subject)
2744b234	273	{
6bff6a60 JH	274	if (keep_subject)
6bff6a60 JH	275	return subject;
2744b234 LT	276	for (;;) {
	277	char *p;
	278	int len, remove;
	279	switch (*subject) {
	280	case 'r': case 'R':
	281	if (!memcmp("e:", subject+1, 2)) {
	282	subject +=3;
	283	continue;
	284	}
	285	break;
	286	case ' ': case '\t': case ':':
	287	subject++;
	288	continue;
	289
	290	case '[':
	291	p = strchr(subject, ']');
	292	if (!p) {
	293	subject++;
	294	continue;
	295	}
	296	len = strlen(p);
	297	remove = p - subject;
	298	if (remove <= len *2) {
	299	subject = p+1;
	300	continue;
	301	}
	302	break;
	303	}
	304	return subject;
	305	}
	306	}
	307
	308	static void cleanup_space(char *buf)
	309	{
	310	unsigned char c;
	311	while ((c = *buf) != 0) {
	312	buf++;
	313	if (isspace(c)) {
	314	buf[-1] = ' ';
	315	c = *buf;
	316	while (isspace(c)) {
	317	int len = strlen(buf);
	318	memmove(buf, buf+1, len);
	319	c = *buf;
	320	}
	321	}
	322	}
	323	}
	324
d4a9ce78 JH	325	typedef int (header_fn_t)(char );
	326	struct header_def {
	327	const char *name;
	328	header_fn_t func;
	329	int namelen;
	330	};
	331
	332	static void check_header(char line, int len, struct header_def header)
	333	{
	334	int i;
	335
	336	if (header[0].namelen <= 0) {
	337	for (i = 0; header[i].name; i++)
	338	header[i].namelen = strlen(header[i].name);
	339	}
	340	for (i = 0; header[i].name; i++) {
	341	int len = header[i].namelen;
	342	if (!strncasecmp(line, header[i].name, len) &&
	343	line[len] == ':' && isspace(line[len + 1])) {
	344	header[i].func(line + len + 2);
	345	break;
	346	}
	347	}
	348	}
	349
	350	static void check_subheader_line(char *line, int len)
	351	{
	352	static struct header_def header[] = {
	353	{ "Content-Type", handle_subcontent_type },
	354	{ "Content-Transfer-Encoding",
	355	handle_content_transfer_encoding },
	356	{ NULL },
	357	};
	358	check_header(line, len, header);
	359	}
	360	static void check_header_line(char *line, int len)
	361	{
	362	static struct header_def header[] = {
	363	{ "From", handle_from },
	364	{ "Date", handle_date },
	365	{ "Subject", handle_subject },
	366	{ "Content-Type", handle_content_type },
	367	{ "Content-Transfer-Encoding",
	368	handle_content_transfer_encoding },
	369	{ NULL },
	370	};
	371	check_header(line, len, header);
	372	}
	373
	374	static int read_one_header_line(char line, int sz, FILE in)
	375	{
	376	int ofs = 0;
	377	while (ofs < sz) {
	378	int peek, len;
	379	if (fgets(line + ofs, sz - ofs, in) == NULL)
	380	return ofs;
	381	len = eatspace(line + ofs);
	382	if (len == 0)
	383	return ofs;
	384	peek = fgetc(in); ungetc(peek, in);
	385	if (peek == ' ' \|\| peek == '\t') {
	386	/* Yuck, 2822 header "folding" */
	387	ofs += len;
	388	continue;
389	}
390	return ofs + len;
391	}
392	return ofs;
393	}
394
395	static unsigned hexval(int c)
396	{
397	if (c >= '0' && c <= '9')
398	return c - '0';
399	if (c >= 'a' && c <= 'f')
400	return c - 'a' + 10;
401	if (c >= 'A' && c <= 'F')
402	return c - 'A' + 10;
403	return ~0;
404	}
405
406	static int decode_q_segment(char in, char ot, char *ep)
407	{
408	int c;
409	while ((c = *in++) != 0 && (in <= ep)) {
410	if (c == '=') {
411	int d = *in++;
412	if (d == '\n' \|\| !d)
413	break; /* drop trailing newline */
414	ot++ = ((hexval(d) << 4) \| hexval(in++));
415	}
416	else
417	*ot++ = c;
418	}
419	*ot = 0;
420	return 0;
421	}
422
423	static int decode_b_segment(char in, char ot, char *ep)
424	{
425	/* Decode in..ep, possibly in-place to ot */
426	int c, pos = 0, acc = 0;
427
428	while ((c = *in++) != 0 && (in <= ep)) {
429	if (c == '+')
430	c = 62;
431	else if (c == '/')
432	c = 63;
433	else if ('A' <= c && c <= 'Z')
434	c -= 'A';
435	else if ('a' <= c && c <= 'z')
436	c -= 'a' - 26;
437	else if ('0' <= c && c <= '9')
438	c -= '0' - 52;
439	else if (c == '=') {
440	/* padding is almost like (c == 0), except we do
441	* not output NUL resulting only from it;
442	* for now we just trust the data.
443	*/
444	c = 0;
445	}
446	else
447	continue; /* garbage */
448	switch (pos++) {
449	case 0:
450	acc = (c << 2);
451	break;
452	case 1:
453	*ot++ = (acc \| (c >> 4));
454	acc = (c & 15) << 4;
455	break;
456	case 2:
457	*ot++ = (acc \| (c >> 2));
458	acc = (c & 3) << 6;
459	break;
460	case 3:
461	*ot++ = (acc \| c);
462	acc = pos = 0;
463	break;
464	}
465	}
466	*ot = 0;
467	return 0;
468	}
469
470	static void convert_to_utf8(char line, char charset)
471	{
650e4be5 JH	472	char in, out;
	473	size_t insize, outsize, nrc;
	474	char outbuf[4096]; /* cheat */
ac44f3e7	475	static char latin_one[] = "latin1";
650e4be5 JH	476	char input_charset = charset ? charset : latin_one;
	477	iconv_t conv = iconv_open(metainfo_charset, input_charset);
	478
	479	if (conv == (iconv_t) -1) {
	480	static int warned_latin1_once = 0;
	481	if (input_charset != latin_one) {
	482	fprintf(stderr, "cannot convert from %s to %s\n",
	483	input_charset, metainfo_charset);
d4a9ce78	484	*charset = 0;
d4a9ce78	485	}
650e4be5 JH	486	else if (!warned_latin1_once) {
	487	warned_latin1_once = 1;
	488	fprintf(stderr, "tried to convert from %s to %s, "
	489	"but your iconv does not work with it.\n",
	490	input_charset, metainfo_charset);
	491	}
	492	return;
d4a9ce78	493	}
650e4be5 JH	494	in = line;
	495	insize = strlen(in);
	496	out = outbuf;
	497	outsize = sizeof(outbuf);
	498	nrc = iconv(conv, &in, &insize, &out, &outsize);
	499	iconv_close(conv);
	500	if (nrc == (size_t) -1)
	501	return;
	502	*out = 0;
	503	strcpy(line, outbuf);
d4a9ce78 JH	504	}
	505
	506	static void decode_header_bq(char *it)
	507	{
	508	char in, out, ep, cp, *sp;
	509	char outbuf[1000];
	510
	511	in = it;
	512	out = outbuf;
	513	while ((ep = strstr(in, "=?")) != NULL) {
	514	int sz, encoding;
	515	char charset_q[256], piecebuf[256];
	516	if (in != ep) {
	517	sz = ep - in;
	518	memcpy(out, in, sz);
	519	out += sz;
	520	in += sz;
	521	}
	522	/* E.g.
	523	* ep : "=?iso-2022-jp?B?GyR...?= foo"
	524	* ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
	525	*/
	526	ep += 2;
	527	cp = strchr(ep, '?');
	528	if (!cp)
	529	return; /* no munging */
	530	for (sp = ep; sp < cp; sp++)
	531	charset_q[sp - ep] = tolower(*sp);
	532	charset_q[cp - ep] = 0;
	533	encoding = cp[1];
	534	if (!encoding \|\| cp[2] != '?')
	535	return; /* no munging */
	536	ep = strstr(cp + 3, "?=");
	537	if (!ep)
	538	return; /* no munging */
	539	switch (tolower(encoding)) {
	540	default:
	541	return; /* no munging */
	542	case 'b':
	543	sz = decode_b_segment(cp + 3, piecebuf, ep);
	544	break;
	545	case 'q':
	546	sz = decode_q_segment(cp + 3, piecebuf, ep);
	547	break;
	548	}
	549	if (sz < 0)
	550	return;
650e4be5	551	if (metainfo_charset)
d4a9ce78 JH	552	convert_to_utf8(piecebuf, charset_q);
	553	strcpy(out, piecebuf);
	554	out += strlen(out);
	555	in = ep + 2;
	556	}
	557	strcpy(out, in);
	558	strcpy(it, outbuf);
	559	}
	560
	561	static void decode_transfer_encoding(char *line)
	562	{
	563	char *ep;
	564
	565	switch (transfer_encoding) {
	566	case TE_QP:
	567	ep = line + strlen(line);
	568	decode_q_segment(line, line, ep);
	569	break;
	570	case TE_BASE64:
	571	ep = line + strlen(line);
	572	decode_b_segment(line, line, ep);
	573	break;
	574	case TE_DONTCARE:
	575	break;
	576	}
	577	}
	578
	579	static void handle_info(void)
2744b234	580	{
d4a9ce78 JH	581	char *sub;
	582	static int done_info = 0;
	583
	584	if (done_info)
	585	return;
	586
	587	done_info = 1;
	588	sub = cleanup_subject(subject);
2744b234	589	cleanup_space(name);
62c1f6b4	590	cleanup_space(date);
2744b234 LT	591	cleanup_space(email);
2744b234 LT	592	cleanup_space(sub);
2744b234	593
d4a9ce78 JH	594	/* Unwrap inline B and Q encoding, and optionally
	595	* normalize the meta information to utf8.
	596	*/
	597	decode_header_bq(name);
	598	decode_header_bq(date);
	599	decode_header_bq(email);
	600	decode_header_bq(sub);
	601	printf("Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
	602	name, email, sub, date);
	603	}
	604
	605	/* We are inside message body and have read line[] already.
	606	* Spit out the commit log.
	607	*/
	608	static int handle_commit_msg(void)
	609	{
	610	if (!cmitmsg)
	611	return 0;
2744b234	612	do {
a196d8d4	613	if (!memcmp("diff -", line, 6) \|\|
fc7ef1e8 LT	614	!memcmp("---", line, 3) \|\|
fc7ef1e8 LT	615	!memcmp("Index: ", line, 7))
d4a9ce78 JH	616	break;
	617	if ((multipart_boundary[0] && is_multipart_boundary(line))) {
	618	/* We come here when the first part had only
	619	* the commit message without any patch. We
	620	* pretend we have not seen this line yet, and
	621	* go back to the loop.
	622	*/
	623	return 1;
	624	}
2744b234	625
d4a9ce78 JH	626	/* Unwrap transfer encoding and optionally
	627	* normalize the log message to UTF-8.
	628	*/
	629	decode_transfer_encoding(line);
650e4be5	630	if (metainfo_charset)
d4a9ce78 JH	631	convert_to_utf8(line, charset);
d4a9ce78 JH	632	fputs(line, cmitmsg);
2744b234	633	} while (fgets(line, sizeof(line), stdin) != NULL);
2744b234	634	fclose(cmitmsg);
d4a9ce78 JH	635	cmitmsg = NULL;
d4a9ce78 JH	636	return 0;
2744b234 LT	637	}
2744b234 LT	638
d4a9ce78 JH	639	/* We have done the commit message and have the first
	640	* line of the patch in line[].
	641	*/
	642	static void handle_patch(void)
2744b234	643	{
d4a9ce78 JH	644	do {
	645	if (multipart_boundary[0] && is_multipart_boundary(line))
	646	break;
	647	/* Only unwrap transfer encoding but otherwise do not
	648	* do anything. We do NOT want UTF-8 conversion
	649	* here; we are dealing with the user payload.
	650	*/
	651	decode_transfer_encoding(line);
	652	fputs(line, patchfile);
	653	patch_lines++;
	654	} while (fgets(line, sizeof(line), stdin) != NULL);
2744b234 LT	655	}
2744b234 LT	656
d4a9ce78 JH	657	/* multipart boundary and transfer encoding are set up for us, and we
	658	* are at the end of the sub header. do equivalent of handle_body up
	659	* to the next boundary without closing patchfile --- we will expect
	660	* that the first part to contain commit message and a patch, and
	661	* handle other parts as pure patches.
	662	*/
	663	static int handle_multipart_one_part(void)
2744b234	664	{
d4a9ce78 JH	665	int seen = 0;
	666	int n = 0;
	667	int len;
2744b234	668
2744b234	669	while (fgets(line, sizeof(line), stdin) != NULL) {
d4a9ce78 JH	670	again:
	671	len = eatspace(line);
	672	n++;
2744b234 LT	673	if (!len)
2744b234 LT	674	continue;
d4a9ce78 JH	675	if (is_multipart_boundary(line))
	676	break;
	677	if (0 <= seen && handle_inbody_header(&seen, line))
	678	continue;
	679	seen = -1; /* no more inbody headers */
2744b234	680	line[len] = '\n';
d4a9ce78 JH	681	handle_info();
	682	if (handle_commit_msg())
	683	goto again;
	684	handle_patch();
2744b234 LT	685	break;
2744b234 LT	686	}
d4a9ce78 JH	687	if (n == 0)
	688	return -1;
	689	return 0;
2744b234 LT	690	}
2744b234 LT	691
d4a9ce78	692	static void handle_multipart_body(void)
1d8fa411	693	{
d4a9ce78 JH	694	int part_num = 0;
	695
	696	/* Skip up to the first boundary */
	697	while (fgets(line, sizeof(line), stdin) != NULL)
	698	if (is_multipart_boundary(line)) {
	699	part_num = 1;
	700	break;
1d8fa411	701	}
d4a9ce78 JH	702	if (!part_num)
	703	return;
	704	/* We are on boundary line. Start slurping the subhead. */
	705	while (1) {
	706	int len = read_one_header_line(line, sizeof(line), stdin);
	707	if (!len) {
	708	if (handle_multipart_one_part() < 0)
	709	return;
	710	}
	711	else
	712	check_subheader_line(line, len);
	713	}
	714	fclose(patchfile);
	715	if (!patch_lines) {
	716	fprintf(stderr, "No patch found\n");
	717	exit(1);
1d8fa411	718	}
1d8fa411 JH	719	}
1d8fa411 JH	720
d4a9ce78 JH	721	/* Non multipart message */
d4a9ce78 JH	722	static void handle_body(void)
2744b234	723	{
d4a9ce78 JH	724	int seen = 0;
	725
	726	while (fgets(line, sizeof(line), stdin) != NULL) {
	727	int len = eatspace(line);
	728	if (!len)
	729	continue;
	730	if (0 <= seen && handle_inbody_header(&seen, line))
	731	continue;
	732	seen = -1; /* no more inbody headers */
	733	line[len] = '\n';
	734	handle_info();
	735	handle_commit_msg();
	736	handle_patch();
	737	break;
	738	}
	739	fclose(patchfile);
	740	if (!patch_lines) {
	741	fprintf(stderr, "No patch found\n");
	742	exit(1);
	743	}
2744b234 LT	744	}
2744b234 LT	745
6bff6a60	746	static const char mailinfo_usage[] =
9f63892b	747	"git-mailinfo [-k] [-u \| --encoding=<encoding>] msg patch <mail >info";
d4a9ce78	748
d4a9ce78	749	int main(int argc, char **argv)
2744b234	750	{
f1f909e3 JH	751	/* NEEDSWORK: might want to do the optional .git/ directory
	752	* discovery
	753	*/
	754	git_config(git_default_config);
	755
6bff6a60 JH	756	while (1 < argc && argv[1][0] == '-') {
	757	if (!strcmp(argv[1], "-k"))
	758	keep_subject = 1;
d4a9ce78	759	else if (!strcmp(argv[1], "-u"))
f1f909e3	760	metainfo_charset = git_commit_encoding;
9f63892b JH	761	else if (!strncmp(argv[1], "--encoding=", 11))
9f63892b JH	762	metainfo_charset = argv[1] + 11;
d4a9ce78	763	else
f1f909e3	764	usage(mailinfo_usage);
6bff6a60 JH	765	argc--; argv++;
	766	}
	767
a196d8d4	768	if (argc != 3)
f1f909e3	769	usage(mailinfo_usage);
2744b234 LT	770	cmitmsg = fopen(argv[1], "w");
	771	if (!cmitmsg) {
	772	perror(argv[1]);
	773	exit(1);
	774	}
	775	patchfile = fopen(argv[2], "w");
	776	if (!patchfile) {
	777	perror(argv[2]);
	778	exit(1);
	779	}
1d8fa411 JH	780	while (1) {
1d8fa411 JH	781	int len = read_one_header_line(line, sizeof(line), stdin);
2744b234	782	if (!len) {
d4a9ce78 JH	783	if (multipart_boundary[0])
	784	handle_multipart_body();
	785	else
	786	handle_body();
2744b234 LT	787	break;
2744b234 LT	788	}
d4a9ce78	789	check_header_line(line, len);
2744b234 LT	790	}
	791	return 0;
	792	}