Add RFC-2047 encoder for internationalized mail warnings.

svn path=/trunk/; revision=3948

3 files changed, 200 insertions, 3 deletions

diff --git a/Makefile.am b/Makefile.am
index d6da0430..cc8cbd15 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -19,7 +19,7 @@ localedir=		$(datadir)/locale
 DEFS=			@DEFS@ -DLOCALEDIR=\"$(localedir)\"
 
 noinst_LIBRARIES=	libfm.a
-libfm_a_SOURCES=	xmalloc.c base64.c rfc822.c report.c
+libfm_a_SOURCES=	xmalloc.c base64.c rfc822.c report.c rfc2047e.c
 libfm_a_LIBADD=		$(EXTRAOBJ)
 libfm_a_DEPENDENCIES=	$(EXTRAOBJ)
 LDADD	=		libfm.a @LIBINTL@ $(LIBOBJS)
@@ -38,9 +38,10 @@ fetchmail_SOURCES=	fetchmail.h getopt.h \
 		smbmd4.c smbutil.c ipv6-connect.c lock.c \
 		rcfile_l.l rcfile_y.y
 
-check_PROGRAMS=	rfc822 unmime netrc
+check_PROGRAMS=	rfc822 unmime netrc rfc2047e
+
+rfc2047e_CFLAGS=	-DTEST
 
-rfc822_SOURCES=	rfc822.c
 rfc822_CFLAGS=	-DMAIN
 
 unmime_SOURCES=	unmime.c
diff --git a/fetchmail.h b/fetchmail.h
index 07b7978b..6de7cf8a 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -654,6 +654,7 @@ int is_host_alias(const char *, struct query *);
 char *host_fqdn(void);
 char *rfc822timestamp(void);
 flag isafile(int);
+char *rfc2047e(const char*, const char *);
 
 void yyerror(const char *);
 int yylex(void);
diff --git a/rfc2047e.c b/rfc2047e.c
new file mode 100644
index 00000000..d42e3046
--- /dev/null
+++ b/rfc2047e.c
@@ -0,0 +1,195 @@
+/*
+    rfc2047e.c - encode a string as per RFC-2047
+    Copyright (C) 2004  Matthias Andree
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#define _GNU_SOURCE
+#include "fetchmail.h"
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+static const char noenc[] = "!\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
+static const char encchars[] = "!\"#$%&'*+,-./0123456789:;<>@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^`abcdefghijklmnopqrstuvwxyz{|}~";
+static const char ws[] = " \t\r\n";
+
+#ifdef TEST
+void report (FILE *fp, const char *format, ...) { (void)fp; (void)format;}
+#endif
+
+static int needs_enc(const char *string) {
+    if (strspn(string, noenc) < strlen(string))
+	return 1;
+    if (strncmp(string, "=?", 2) == 0
+	    && strcmp(string + strlen(string) - 2, "?=") == 0)
+	return 1;
+    return 0;
+}
+
+static char *encode_words(char *const *words, int nwords, const char *charset)
+{
+    char *out, *t, *v;
+    size_t l = 0;
+    int i;
+
+    for (i = 0; i < nwords; i++)
+	l += strlen(words[i]) * 3; /* worst case, encode everything */
+    l += (strlen(charset) + 8) * (l/60 + 1);
+
+    out = v = xmalloc(l);
+    t = stpcpy(out, "=?");
+    t = stpcpy(t, charset);
+    t = stpcpy(t, "?Q?");
+    for (i = 0; i < nwords; i++) {
+	const char *u;
+	for (u = words[i]; *u; u++) {
+	    if (t - v >= 69) {
+		t = stpcpy(t, "?=\r\n=?");
+		v = t - 2;
+		t = stpcpy(t, charset);
+		t = stpcpy(t, "?Q?");
+	    }
+	    if (*u == ' ') { *t++ = '_'; continue; }
+	    if (strchr(encchars, *u)) { *t++ = *u; continue; }
+	    sprintf(t, "=%02X", (unsigned char)*u);
+	    t += 3;
+	}
+    }
+    strcpy(t, "?=");
+    return out;
+}
+
+char *rfc2047e(const char *string, const char *charset) {
+    char *t, *out;
+    const char *r;
+    int count, minlen, idx, i;
+    char **words = NULL;
+    size_t l;
+
+    assert(strlen(charset) < 40);
+
+    /* phase 1: split original into words */
+    /* 1a: count, 1b: copy */
+    count = 0;
+    r = string;
+    while (*r) {
+	count++;
+	r += strcspn(r, ws);
+	if (!*r) break;
+	count++;
+	r += strspn(r, ws);
+    }
+    words = xmalloc(sizeof(char *) * (count + 1));
+
+    idx = 0;
+    r = string;
+    while (*r) {
+	l = strcspn(r, ws);
+	words[idx] = xmalloc(l+1);
+	memcpy(words[idx], r, l);
+	words[idx][l] = 0;
+	idx++;
+	r += l;
+	if (!*r) break;
+	l = strspn(r, ws);
+	words[idx] = xmalloc(l+1);
+	memcpy(words[idx], r, l);
+	words[idx][l] = 0;
+	idx++;
+	r += l;
+    }
+
+    /* phase 2: encode words */
+    /* a: find ranges of adjacent words to need encoding */
+    /* b: encode ranges */
+
+    idx = 0;
+    while (idx < count) {
+	int end; char *tmp;
+
+	if (!needs_enc(words[idx])) {
+	    idx += 2;
+	    continue;
+	}
+	for (end = idx + 2; end < count; end += 2) {
+	    if (!needs_enc(words[end]))
+		break;
+	}
+	end -= 2;
+	tmp = encode_words(&words[idx], end - idx + 1, charset);
+	free(words[idx]);
+	words[idx] = tmp;
+	for (i = idx + 1; i <= end; i++)
+	    words[i][0] = 0;
+	idx = end + 2;
+    }
+
+    for (idx = l = 0; idx < count; idx++) {
+	l += strlen(words[idx]);
+    }
+
+    /* phase 3: limit lengths */
+    minlen = strlen(charset) + 7;
+    /* allocate ample memory */
+    out = xmalloc(l + (l / (72 - minlen) + 1) * (minlen + 2) + 1);
+
+    if (count)
+	t = stpcpy(out, words[0]);
+    else
+	t = out, *out = 0;
+
+    l = strlen(out);
+
+    for (i = 1; i < count; i+=2) {
+	size_t m;
+	char *tmp;
+
+	m = strlen(words[i]);
+	if (i + 1 < count)
+	    m += strcspn(words[i+1], "\r\n");
+	if (l + m > 74)
+	    l = 0, t = stpcpy(t, "\r\n");
+	t = stpcpy(t, words[i]);
+	if (i + 1 < count) {
+	    t = stpcpy(t, words[i+1]);
+	}
+	tmp = strrchr(out, '\n');
+	if (!tmp) tmp = out; else tmp++;
+	l = strlen(tmp);
+    }
+
+    /* free memory */
+    for (i = 0; i < count; i++) free(words[i]);
+    free(words);
+    return out;
+}
+
+#ifdef TEST
+int main(int argc, char **argv) {
+    char *t;
+
+    if (argc > 1) {
+	t = rfc2047e(argv[1], argc > 2 ? argv[2] : "utf-8");
+	printf( " input: \"%s\"\n"
+		"output: \"%s\"\n", argv[1], t);
+	free(t);
+    }
+    return EXIT_SUCCESS;
+}
+#endif