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From: Robert Luberda <robert@debian.org>
Date: Thu, 13 Apr 2017 23:39:39 +0200
Subject: Add MIME headers unless set by user
Generate the three following headers by default:
MIME-Version: 1.0
Content-Type: text/plain; charset="<current charset from $LC_CTYPE>"
Content-Transfer-Encoding: 8bit
However allow a user to override each of them with the -a flag.
Example:
bsd-mailx -a "Content-Type: text/html; charset=UTF-8"
uses the above user-provided Content-Type, but still adds
the default MIME-Version and Content-Transfer-Encoding headers.
Bugs-Debian: https://bugs.debian.org/859935
mail.1 | 28 +++++++++++++++++++++++++++-
main.c | 4 ++++
send.c | 43 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 74 insertions(+), 1 deletion(-)
diff --git a/mail.1 b/mail.1
index 5683e56..f429557 100644
@@ -67,7 +67,13 @@ The options are as follows:
.Bl -tag -width Ds
.It Fl a
Specify additional header fields on the command line such as "X-Loop:
-foo@bar" etc. You have to use quotes if the string contains spaces.
+foo@bar" etc.
+It can be also used to override MIME headers
+.Nm mail
+adds by default to each outgoing mail, see
+.Sx Character sets and MIME
+below.
+You have to use quotes if the string contains spaces.
This argument may be specified more than once, the headers will then
be concatenated.
.It Fl b Ar bcc-addr
@@ -366,6 +372,26 @@ If the
.Ic expandaddr
option is not set (the default), no expansion is performed and
the recipient is treated as a local or network mail address.
+.Ss Character sets and MIME
+Generally
+.Nm mail
+does not handle neither different character sets nor any other MIME
+feature. Especially it does not perform any any conversions between
+character sets while displaying or sending mails.
+.Pp
+Starting from April 2017, however, as a Debian extension this version of
+.Nm mail
+adds a few MIME headers to every outgoing mail in order to indicate
+that the mail is sent as 8-bit plain text data that uses character
+set encoding detected from the current
+.Xr locale 7
+settings.
+The
+.Fl a
+command-line option can be used to override those headers, for example:
+.Dl $ mail -a 'Content-Type: text/plain; charset="ISO-8859-1"'
+sets header indicating legacy character encoding.
+.Pp
.Sh SUMMARY
(Adapted from the
.Dq Mail Reference Manual . )
diff --git a/main.c b/main.c
index 07ad856..4cba833 100644
@@ -34,6 +34,7 @@
#include <fcntl.h>
#include <sys/ioctl.h>
#include "extern.h"
+#include <locale.h>
static void usage(void);
int main(int, char **);
@@ -70,6 +71,9 @@ main(int argc, char **argv)
err(1, "setuid");
}
+ /* Set the current user locale's charset. */
+ setlocale(LC_CTYPE, "");
+
/*
* Set up a reasonable environment.
* Figure out whether we are being run interactively,
diff --git a/send.c b/send.c
index cc75f49..771ecc9 100644
@@ -30,6 +30,7 @@
* SUCH DAMAGE.
*/
+#include <langinfo.h>
#include <time.h>
#include "rcv.h"
#include "extern.h"
@@ -558,6 +559,36 @@ infix(struct header *hp, FILE *fi)
rewind(nfi);
return(nfi);
}
+/*
+ * Check if headers (a list separated by new line characters) contains a header
+ * which name is given in the headername argument of length given in headernamelen.
+ */
+static int hasheader(const char* headers, const char* const headername, const size_t headernamelen)
+{
+ while (headers) {
+ /* Skip leading white spaces, including '\n' from
+ * the previous iteration of the loop
+ */
+ while (isspace(*headers))
+ ++headers;
+
+ if (strncasecmp(headers, headername, headernamelen) == 0) {
+ /* Found a match, check if it is followed by ':' */
+ const char* end = headers + headernamelen;
+ /* Permit optional white spaces before ':' */
+ while (isspace(*end) && *end != '\n')
+ ++end;
+
+ if (*end == ':')
+ return 1;
+
+ headers = end; /* Small optimization for the following strchr() call */
+ }
+
+ headers = strchr(headers, '\n'); /* Find start of the next header */
+ }
+ return 0;
+}
/*
* Dump the to, subject, cc header on the
@@ -583,6 +614,18 @@ puthead(struct header *hp, FILE *fo, int w)
fmt("Bcc:", hp->h_bcc, fo, w&GCOMMA), gotcha++;
if (hp->h_header != NULL && w)
fprintf(fo, "%s\n", hp->h_header), gotcha++;
+ if (w)
+ {
+#define ADDHEADER(name, value, ...) if (!hasheader(hp->h_header, name, sizeof(name) - 1)) \
+ fprintf(fo, name ": " value "\n", ##__VA_ARGS__), gotcha++
+
+ const char* const cs = nl_langinfo(CODESET);
+ ADDHEADER("MIME-Version", "1.0");
+ ADDHEADER("Content-Type", "text/plain; charset=\"%s\"",
+ cs && *cs ? cs : "ANSI_X3.4-1968");
+ ADDHEADER("Content-Transfer-Encoding", "8bit");
+#undef ADDHEADER
+ }
if (hp->h_replyto != NULL && w & GREPLYTO)
fprintf(fo, "Reply-To: %s\n", hp->h_replyto), gotcha++;
if (hp->h_inreplyto != NULL && w & GINREPLYTO)
|
