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, 7 insertions, 1 deletions

diff --git a/t/solver_git.t b/t/solver_git.t
index 75387b2a..e566efb3 100644
--- a/t/solver_git.t
+++ b/t/solver_git.t
@@ -32,7 +32,7 @@ my $v1_0_0_tag_short = substr($v1_0_0_tag, 0, 16);
 my $expect = '69df7d565d49fbaaeb0a067910f03dc22cd52bd0';
 my $non_existent = 'ee5e32211bf62ab6531bdf39b84b6920d0b6775a';
 
-test_lei({tmpdir => $tmpdir}, sub {
+test_lei({tmpdir => "$tmpdir/blob"}, sub {
         lei_ok('blob', '--mail', $patch2_oid, '-I', $ibx->{inboxdir},
                 \'--mail works for existing oid');
         is($lei_out, $patch2->as_string, 'blob matches');
@@ -64,6 +64,12 @@ test_lei({tmpdir => $tmpdir}, sub {
         lei_ok('blob', $v1_0_0_tag_short, '-I', $ibx->{inboxdir});
 });
 
+test_lei({tmpdir => "$tmpdir/rediff"}, sub {
+        lei_ok(qw(rediff -q -U9 t/solve/0001-simple-mod.patch));
+        like($lei_out, qr!^\Q+++\E b/TODO\n@@ -103,9 \+103,11 @@!sm,
+                'got more context with -U9');
+});
+
 my $git = PublicInbox::Git->new($git_dir);
 $ibx->{-repo_objs} = [ $git ];
 my $res;