solver: path_a may be undef from /dev/null

This avoids uninitialized variable warnings when viewing
newly-created files.

diff --git a/lib/PublicInbox/SolverGit.pm b/lib/PublicInbox/SolverGit.pm
index b48e8ac429e8676687ad97919a1bcfb373b17f7e..baad981de8f6fbbae60bb812d610be15858fb25e 100644 (file)
--- a/lib/PublicInbox/SolverGit.pm
+++ b/lib/PublicInbox/SolverGit.pm
@@ -169,7 +169,7 @@ sub extract_diff ($$) {
        my $patch = $9;
 
        # don't care for leading 'a/' and 'b/'
-       my (undef, @a) = split(m{/}, git_unquote($path_a));
+       my (undef, @a) = split(m{/}, git_unquote($path_a)) if defined($path_a);
        my (undef, @b) = split(m{/}, git_unquote($path_b));
 
        # get rid of path-traversal attempts and junk patches:
@@ -177,7 +177,7 @@ sub extract_diff ($$) {
        state $bad_component = { map { $_ => 1 } ('', '.', '..') };
        foreach (@a, @b) { return if $bad_component->{$_} }
 
-       $di->{path_a} = join('/', @a);
+       $di->{path_a} = join('/', @a) if @a;
        $di->{path_b} = join('/', @b);
 
        my $path = ++$self->{tot};