git-send-email: delay creation of MIME headers

After the next patch, git-send-email will sometimes modify
existing Content-Transfer-Encoding headers.  Delay the addition
of the header to @xh until just before sending.  Do the same
for MIME-Version, to avoid adding it twice.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-send-email.perl b/git-send-email.perl
index 9949db01e11959c81fae75fa018551601e6d5c3b..b29a3045b7d91eb6c9543559e0cb909219a826dd 100755 (executable)
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -1324,6 +1324,8 @@ sub send_message {
        my $author_encoding;
        my $has_content_type;
        my $body_encoding;
+       my $xfer_encoding;
+       my $has_mime_version;
        @to = ();
        @cc = ();
        @xh = ();
@@ -1394,9 +1396,16 @@ sub send_message {
                                }
                                push @xh, $_;
                        }
+                       elsif (/^MIME-Version/i) {
+                               $has_mime_version = 1;
+                               push @xh, $_;
+                       }
                        elsif (/^Message-Id: (.*)/i) {
                                $message_id = $1;
                        }
+                       elsif (/^Content-Transfer-Encoding: (.*)/i) {
+                               $xfer_encoding = $1 if not defined $xfer_encoding;
+                       }
                        elsif (!/^Date:\s/i && /^[-A-Za-z]+:\s+\S/) {
                                push @xh, $_;
                        }
@@ -1444,10 +1453,9 @@ sub send_message {
                if defined $cc_cmd && !$suppress_cc{'cccmd'};
 
        if ($broken_encoding{$t} && !$has_content_type) {
+               $xfer_encoding = '8bit' if not defined $xfer_encoding;
                $has_content_type = 1;
-               push @xh, "MIME-Version: 1.0",
-                       "Content-Type: text/plain; charset=$auto_8bit_encoding",
-                       "Content-Transfer-Encoding: 8bit";
+               push @xh, "Content-Type: text/plain; charset=$auto_8bit_encoding";
                $body_encoding = $auto_8bit_encoding;
        }
 
@@ -1467,14 +1475,19 @@ sub send_message {
                                }
                        }
                        else {
+                               $xfer_encoding = '8bit' if not defined $xfer_encoding;
                                $has_content_type = 1;
                                push @xh,
-                                 'MIME-Version: 1.0',
-                                 "Content-Type: text/plain; charset=$author_encoding",
-                                 'Content-Transfer-Encoding: 8bit';
+                                 "Content-Type: text/plain; charset=$author_encoding";
                        }
                }
        }
+       if (defined $xfer_encoding) {
+               push @xh, "Content-Transfer-Encoding: $xfer_encoding";
+       }
+       if (defined $xfer_encoding or $has_content_type) {
+               unshift @xh, 'MIME-Version: 1.0' unless $has_mime_version;
+       }
 
        $needs_confirm = (
                $confirm eq "always" or