lei rediff: regenerate diffs from stdin

Sometimes a mailed patch is generated with non-ideal output,
(lacking context, noisy whitespace changes, etc.), or a user
wants to use the same external diff viewer they've configured
git to use.

Since we have SolverGit to regenerate arbitrary blobs from
patches; this new command allows us to regenerate a diff with
different options using the blobs SolverGit gives us.

The amount of git-diff(1) options is mind numbing, so it's
likely I missed some favorites or botched the getopt spec
translation.

This also fixes Inbox::base_url to check psgi.url_scheme
before attempting to generate URLs and avoid uninitialized
variable warnings.  Oddly, the "lei blob" tests did not
trigger these uninitialized warnings.

Note: this will automatically import+index the message(s)
it's regenerating, because solver relies on being able
to lookup pre/postimage OIDs and read blobs.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/Inbox.pm b/lib/PublicInbox/Inbox.pm
index da7ea75f..b94ffdb0 100644
--- a/lib/PublicInbox/Inbox.pm
+++ b/lib/PublicInbox/Inbox.pm
@@ -241,7 +241,7 @@ sub cloneurl {
 
 sub base_url {
         my ($self, $env) = @_; # env - PSGI env
-        if ($env) {
+        if ($env && $env->{'psgi.url_scheme'}) {
                 my $url = PublicInbox::Git::host_prefix_url($env, '');
                 # for mount in Plack::Builder
                 $url .= '/' if $url !~ m!/\z!;