return ret;
 }
 
+/*
+ * Returns 1 if the given line or any line beginning with the given line is an
+ * in-body header (that is, check_header will succeed when passed
+ * mi->s_hdr_data).
+ */
+static int is_inbody_header(const struct mailinfo *mi,
+                           const struct strbuf *line)
+{
+       int i;
+       for (i = 0; header[i]; i++)
+               if (!mi->s_hdr_data[i] && cmp_header(line, header[i]))
+                       return 1;
+       return 0;
+}
+
 static void decode_transfer_encoding(struct mailinfo *mi, struct strbuf *line)
 {
        struct strbuf *ret;
                gap * 2 < perforation);
 }
 
+static void flush_inbody_header_accum(struct mailinfo *mi)
+{
+       if (!mi->inbody_header_accum.len)
+               return;
+       assert(check_header(mi, &mi->inbody_header_accum, mi->s_hdr_data, 0));
+       strbuf_reset(&mi->inbody_header_accum);
+}
+
 static int check_inbody_header(struct mailinfo *mi, const struct strbuf *line)
 {
+       if (mi->inbody_header_accum.len &&
+           (line->buf[0] == ' ' || line->buf[0] == '\t')) {
+               if (mi->use_scissors && is_scissors_line(line->buf)) {
+                       /*
+                        * This is a scissors line; do not consider this line
+                        * as a header continuation line.
+                        */
+                       flush_inbody_header_accum(mi);
+                       return 0;
+               }
+               strbuf_strip_suffix(&mi->inbody_header_accum, "\n");
+               strbuf_addbuf(&mi->inbody_header_accum, line);
+               return 1;
+       }
+
+       flush_inbody_header_accum(mi);
+
        if (starts_with(line->buf, ">From") && isspace(line->buf[5]))
                return is_format_patch_separator(line->buf + 1, line->len - 1);
        if (starts_with(line->buf, "[PATCH]") && isspace(line->buf[7])) {
                        }
                return 0;
        }
-       return check_header(mi, line, mi->s_hdr_data, 0);
+       if (is_inbody_header(mi, line)) {
+               strbuf_addbuf(&mi->inbody_header_accum, line);
+               return 1;
+       }
+       return 0;
 }
 
 static int handle_commit_msg(struct mailinfo *mi, struct strbuf *line)
                        break;
        } while (!strbuf_getwholeline(line, mi->input, '\n'));
 
+       flush_inbody_header_accum(mi);
+
 handle_body_out:
        strbuf_release(&prev);
 }
        strbuf_init(&mi->email, 0);
        strbuf_init(&mi->charset, 0);
        strbuf_init(&mi->log_message, 0);
+       strbuf_init(&mi->inbody_header_accum, 0);
        mi->header_stage = 1;
        mi->use_inbody_headers = 1;
        mi->content_top = mi->content;
        strbuf_release(&mi->name);
        strbuf_release(&mi->email);
        strbuf_release(&mi->charset);
+       strbuf_release(&mi->inbody_header_accum);
        free(mi->message_id);
 
        for (i = 0; mi->p_hdr_data[i]; i++)
 
        test_cmp msg out
 '
 
+test_expect_success 'am works with multi-line in-body headers' '
+       FORTY="String that has a length of more than forty characters" &&
+       LONG="$FORTY $FORTY" &&
+       rm -fr .git/rebase-apply &&
+       git checkout -f first &&
+       echo one >> file &&
+       git commit -am "$LONG" --author="$LONG <long@example.com>" &&
+       git format-patch --stdout -1 >patch &&
+       # bump from, date, and subject down to in-body header
+       perl -lpe "
+               if (/^From:/) {
+                       print \"From: x <x\@example.com>\";
+                       print \"Date: Sat, 1 Jan 2000 00:00:00 +0000\";
+                       print \"Subject: x\n\";
+               }
+       " patch >msg &&
+       git checkout HEAD^ &&
+       git am msg &&
+       # Ensure that the author and full message are present
+       git cat-file commit HEAD | grep "^author.*long@example.com" &&
+       git cat-file commit HEAD | grep "^$LONG"
+'
+
 test_done