Don't use author date as email date

This can be months in the past, and means people who sort their
messages by date won't see commits.  Ideally, we'd set this to the
time of the push, but since that information isn't exposed, the best
we can do is the time when we saw it.

Author and committer dates are now both included in the message
header.

1 files changed, 20 insertions, 3 deletions

diff --git a/src/main.rs b/src/main.rs
index e2587f8..4120c0d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -41,6 +41,7 @@
 
 mod util;
 
+use chrono::prelude::*;
 use clap::clap_app;
 use failure::{err_msg, format_err, Error};
 use isahc::prelude::*;
@@ -151,7 +152,7 @@ impl<S: AsRef<OsStr>> Git<S> {
         argv.extend_from_slice(&c_global_args);
         argv.push(b"show\0" as *const _);
         argv.push(b"--no-patch\0" as *const _);
-        argv.push(b"--format=Committer: %cn <%ce>\0" as *const _);
+        argv.push(b"--format=Date: %aD%nCommit: %cn <%ce>%nCommitDate: %cD\0" as *const _);
         argv.push(range.as_ptr());
         argv.push(null());
 
@@ -380,6 +381,7 @@ impl<'a> Run<'a> {
 
         for line in patch {
             let line = line?;
+            let mut write = true;
 
             let new_state = match (state, line.as_slice()) {
                 (Header, b"") => MessageHeader,
@@ -390,6 +392,19 @@ impl<'a> Run<'a> {
             };
 
             match (state, new_state) {
+                (Header, Header) => {
+                    if line
+                        .iter()
+                        .map(u8::to_ascii_lowercase)
+                        .take(5)
+                        .collect::<Vec<_>>()
+                        == b"date:"
+                    {
+                        write!(sendmail_in, "Date: {}\n", Local::now().to_rfc2822())?;
+                        write = false;
+                    }
+                }
+
                 (MessageHeader, Message) => {
                     self.git
                         .git_print_user_info(sendmail_in, OsStr::new(commit))?;
@@ -402,8 +417,10 @@ impl<'a> Run<'a> {
                 _ => {}
             }
 
-            sendmail_in.write_all(&line)?;
-            sendmail_in.write_all(b"\n")?;
+            if write {
+                sendmail_in.write_all(&line)?;
+                sendmail_in.write_all(b"\n")?;
+            }
 
             state = new_state;
         }