From c9076497c235510f9358f9e3eadfe91fbfa9d5e3 Mon Sep 17 00:00:00 2001
From: Philipp Takacs <philipp@bureaucracy.de>
Date: Fri, 25 Aug 2023 20:28:55 +0200
Subject: [PATCH] mhbuild implement header folding
---
h/mh.h | 2 ++
h/prototypes.h | 1 +
sbr/Makefile.in | 3 +-
sbr/fold.c | 61 +++++++++++++++++++++++++++++++++
test/tests/mhbuild/test-folding | 35 +++++++++++++++++++
uip/mhoutsbr.c | 5 ++-
6 files changed, 105 insertions(+), 2 deletions(-)
create mode 100644 sbr/fold.c
create mode 100644 test/tests/mhbuild/test-folding
diff --git a/h/mh.h b/h/mh.h
index 33261856..280249e1 100644
--- a/h/mh.h
+++ b/h/mh.h
@@ -221,6 +221,8 @@ struct msgs {
** terminating NULL.
*/
+#define MAXTEXTPERLN 78
+
/* m_getfld2() returned data */
struct field {
char name[NAMESZ];
diff --git a/h/prototypes.h b/h/prototypes.h
index fad1af4f..182cf1c5 100644
--- a/h/prototypes.h
+++ b/h/prototypes.h
@@ -114,6 +114,7 @@ void unquote_string(const char *input, char *output);
int uprf(char *, char *);
int vfgets(FILE *, char **);
char *write_charset_8bit(void);
+void fold(charstring_t, size_t, const char *restrict);
diff --git a/sbr/Makefile.in b/sbr/Makefile.in
index cee1c453..ca8b20da 100644
--- a/sbr/Makefile.in
+++ b/sbr/Makefile.in
@@ -54,7 +54,8 @@ SRCS = addrsbr.c ambigsw.c brkstring.c \
cpydata.c crawl_folders.c \
charstring.c \
dtime.c dtimep.c \
- error.c execprog.c ext_hook.c folder_addmsg.c folder_delmsgs.c \
+ error.c execprog.c ext_hook.c fold.c \
+ folder_addmsg.c folder_delmsgs.c \
folder_free.c folder_read.c \
folder_realloc.c gans.c getans.c getanswer.c \
getarguments.c \
diff --git a/sbr/fold.c b/sbr/fold.c
new file mode 100644
index 00000000..01893827
--- /dev/null
+++ b/sbr/fold.c
@@ -0,0 +1,61 @@
+/* fold.c -- fold a mail header field
+ *
+ * This code is Copyright (c), by the authors of nmh. See the
+ * COPYRIGHT file in the root directory of the nmh distribution for
+ * complete copyright information. */
+
+#include <h/mh.h>
+#include <stdio.h>
+
+void
+fold(charstring_t dst, size_t namelen, const char *restrict body)
+{
+ const char *restrict body_next;
+ const char *restrict wsp;
+ const char *restrict wsp_next;
+ const int crlf = strchr(body, '\r') != NULL;
+ charstring_clear(dst);
+ namelen++;
+
+ while (*body) {
+ body_next = strchr(body, '\n');
+ if ((unsigned long) (body_next - body) <= MAXTEXTPERLN - namelen) {
+ charstring_push_back_chars(dst, body, body_next - body + 1);
+ namelen = 0;
+ body = body_next + 1;
+ continue;
+ }
+ wsp = body;
+ while (namelen == 0 && (*wsp == ' ' || *wsp == '\t')) {
+ wsp++;
+ }
+ wsp = wsp_next = strpbrk(wsp, " \t");
+
+ /* if now whitespace is in the current line just print the curret line as is */
+ if (!wsp_next || wsp_next > body_next) {
+ charstring_push_back_chars(dst, body, body_next - body + 1);
+ namelen = 0;
+ body = body_next + 1;
+ continue;
+ }
+
+ while ((unsigned long)(wsp_next - body) <= MAXTEXTPERLN - namelen) {
+ wsp = wsp_next;
+ wsp_next = strpbrk(wsp+1, " \t");
+ if (!wsp_next) {
+ break;
+ }
+ if (wsp_next > body_next) {
+ break;
+ }
+ }
+
+ charstring_push_back_chars(dst, body, wsp - body);
+ if (crlf) {
+ charstring_push_back(dst, '\r');
+ }
+ charstring_push_back(dst, '\n');
+ namelen = 0;
+ body = wsp;
+ }
+}
diff --git a/test/tests/mhbuild/test-folding b/test/tests/mhbuild/test-folding
new file mode 100644
index 00000000..366f82b5
--- /dev/null
+++ b/test/tests/mhbuild/test-folding
@@ -0,0 +1,35 @@
+# test mhbuild linebreak for quoted-printable
+
+. "$MH_TEST_COMMON"
+
+
+draft="$MH_TEST_DIR/mhbuild-$$.draft"
+
+cat >"$draft" <<!
+From: meillo
+To: meillo
+Date: Thursday, 28 Sep 2006 00:02:00
+Subject: mhbuild header folding
+References: <aaaaaaaaaaaaaaaaaaaaaaaaaaa@example.com> <aaaaaaaaaaaaaaaaaaaaaaaaaab@example.com> <c@example.com>
+----------------
+Das ist ein test
+!
+
+
+
+runandcheck 'mhbuild "$draft"' <<!
+!
+
+runandcheck 'sed "/^Content-ID:/s/:.*/: <TESTID>/" "$draft"' <<!
+From: meillo
+To: meillo
+Date: Thursday, 28 Sep 2006 00:02:00
+Subject: mhbuild header folding
+References: <aaaaaaaaaaaaaaaaaaaaaaaaaaa@example.com>
+ <aaaaaaaaaaaaaaaaaaaaaaaaaab@example.com> <c@example.com>
+MIME-Version: 1.0
+Content-Type: text/plain; charset="us-ascii"
+Content-ID: <TESTID>
+
+Das ist ein test
+!
diff --git a/uip/mhoutsbr.c b/uip/mhoutsbr.c
index 87e7943c..2915afe3 100644
--- a/uip/mhoutsbr.c
+++ b/uip/mhoutsbr.c
@@ -161,12 +161,15 @@ static void
output_headers(CT ct, FILE *out)
{
HF hp;
+ charstring_t body = charstring_create(0);
hp = ct->c_first_hf;
while (hp) {
- fprintf(out, "%s:%s", hp->name, hp->value);
+ fold(body, strlen(hp->name), hp->value);
+ fprintf(out, "%s:%s", hp->name, charstring_buffer(body));
hp = hp->next;
}
+ charstring_free(body);
}
--
2.39.5