Index: branches/release-41/lib/MT/Template/ContextHandlers.pm
===================================================================
--- branches/release-41/lib/MT/Template/ContextHandlers.pm (revision 2684)
+++ branches/release-41/lib/MT/Template/ContextHandlers.pm (revision 2696)
@@ -6544,5 +6544,14 @@
     return $ctx->_no_author_error() unless $author;
     my $size = $args->{size} || 'logo_small';
-    return $author->auth_icon_url($size);
+    my $url = $author->auth_icon_url($size);
+    if ($url =~ m!^/!) {
+        # relative path, prepend blog domain
+        my $blog = $ctx->stash('blog');
+        if ($blog) {
+            my ($blog_domain) = $blog->archive_url =~ m|(.+://[^/]+)|;
+            $url = $blog_domain . $url;
+        }
+    }
+    return $url;
 }
 
@@ -11164,5 +11173,14 @@
     return q() unless $a;
     my $size = $args->{size} || 'logo_small';
-    return $a->auth_icon_url($size);
+    my $url = $a->auth_icon_url($size);
+    if ($url =~ m!^/!) {
+        # relative path, prepend blog domain
+        my $blog = $ctx->stash('blog');
+        if ($blog) {
+            my ($blog_domain) = $blog->archive_url =~ m|(.+://[^/]+)|;
+            $url = $blog_domain . $url;
+        }
+    }
+    return $url;
 }