CMIT_FMT_EMAIL: Q-encode Subject: and display-name part of From: fields.

By convention, the commit message and the author/committer names
in the commit objects are UTF-8 encoded.  When formatting for
e-mails, Q-encode them according to RFC 2047.

While we are at it, generate the content-type and
content-transfer-encoding headers as well.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/commit.c b/commit.c
index 0b163d4..7597fba 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -422,6 +422,46 @@ static int get_one_line(const char *msg, unsigned long len)
        return ret;
 }
 
+static int is_rfc2047_special(char ch)
+{
+       return ((ch & 0x80) || (ch == '=') || (ch == '?') || (ch == '_'));
+}
+
+static int add_rfc2047(char *buf, const char *line, int len)
+{
+       char *bp = buf;
+       int i, needquote;
+       static const char q_utf8[] = "=?utf-8?q?";
+
+       for (i = needquote = 0; !needquote && i < len; i++) {
+               unsigned ch = line[i];
+               if (ch & 0x80)
+                       needquote++;
+               if ((i + 1 < len) &&
+                   (ch == '=' && line[i+1] == '?'))
+                       needquote++;
+       }
+       if (!needquote)
+               return sprintf(buf, "%.*s", len, line);
+
+       memcpy(bp, q_utf8, sizeof(q_utf8)-1);
+       bp += sizeof(q_utf8)-1;
+       for (i = 0; i < len; i++) {
+               unsigned ch = line[i];
+               if (is_rfc2047_special(ch)) {
+                       sprintf(bp, "=%02X", ch);
+                       bp += 3;
+               }
+               else if (ch == ' ')
+                       *bp++ = '_';
+               else
+                       *bp++ = ch;
+       }
+       memcpy(bp, "?=", 2);
+       bp += 2;
+       return bp - buf;
+}
+
 static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const char *line)
 {
        char *date;
@@ -440,12 +480,26 @@ static int add_user_info(const char *what, enum cmit_fmt fmt, char *buf, const c
        tz = strtol(date, NULL, 10);
 
        if (fmt == CMIT_FMT_EMAIL) {
-               what = "From";
+               char *name_tail = strchr(line, '<');
+               int display_name_length;
+               if (!name_tail)
+                       return 0;
+               while (line < name_tail && isspace(name_tail[-1]))
+                       name_tail--;
+               display_name_length = name_tail - line;
                filler = "";
+               strcpy(buf, "From: ");
+               ret = strlen(buf);
+               ret += add_rfc2047(buf + ret, line, display_name_length);
+               memcpy(buf + ret, name_tail, namelen - display_name_length);
+               ret += namelen - display_name_length;
+               buf[ret++] = '\n';
+       }
+       else {
+               ret = sprintf(buf, "%s: %.*s%.*s\n", what,
+                             (fmt == CMIT_FMT_FULLER) ? 4 : 0,
+                             filler, namelen, line);
        }
-       ret = sprintf(buf, "%s: %.*s%.*s\n", what,
-                     (fmt == CMIT_FMT_FULLER) ? 4 : 0,
-                     filler, namelen, line);
        switch (fmt) {
        case CMIT_FMT_MEDIUM:
                ret += sprintf(buf + ret, "Date:   %s\n", show_date(time, tz));
@@ -584,13 +638,24 @@ unsigned long pretty_print_commit(enum cmit_fmt fmt, const struct commit *commit
                        int slen = strlen(subject);
                        memcpy(buf + offset, subject, slen);
                        offset += slen;
+                       offset += add_rfc2047(buf + offset, line, linelen);
+               }
+               else {
+                       memset(buf + offset, ' ', indent);
+                       memcpy(buf + offset + indent, line, linelen);
+                       offset += linelen + indent;
                }
-               memset(buf + offset, ' ', indent);
-               memcpy(buf + offset + indent, line, linelen);
-               offset += linelen + indent;
                buf[offset++] = '\n';
                if (fmt == CMIT_FMT_ONELINE)
                        break;
+               if (subject) {
+                       static const char header[] =
+                               "Content-Type: text/plain; charset=UTF-8\n"
+                               "Content-Transfer-Encoding: 8bit\n";
+                       memcpy(buf + offset, header, sizeof(header)-1);
+                       offset += sizeof(header)-1;
+                       subject = NULL;
+               }
                if (after_subject) {
                        int slen = strlen(after_subject);
                        if (slen > space - offset - 1)