External scripts are not enqueued with necessary dependencies

[emrikol]

do_item() is called to let core handle external scripts, since they don't get concatenated. Unfortunately, $this->do_concat is true, so the external script tag is saved for later instead of being echo'd at the proper time for its dependents/dependencies

I've got a patch (below) but I'm not 100% sure enough to know that it wouldn't break other things. It likely needs cleaned up and tested more.

diff --git a/jsconcat.php b/jsconcat.php
index b46a4b5..ae8c61a 100644
--- a/jsconcat.php
+++ b/jsconcat.php
@@ -39,6 +39,7 @@ class WPcom_JS_Concat extends WP_Scripts {
                $handles = false === $handles ? $this->queue : (array) $handles;
                $javascripts= array();
                $siteurl = site_url();
+               $external_scripts = array();

                $this->all_deps( $handles );
                $level = 0;
@@ -73,8 +74,10 @@ class WPcom_JS_Concat extends WP_Scripts {
                                $do_concat = true;

                        // Don't try to concat externally hosted scripts
-                       if ( ( isset( $js_url['host'] ) && ( preg_replace( '/https?:\/\//', '', $siteurl ) != $js_url['host'] ) ) )
+                       if ( ( isset( $js_url['host'] ) && ( preg_replace( '/https?:\/\//', '', $siteurl ) != $js_url['host'] ) ) ) {
+                               $external_scripts[] = $handle;
                                $do_concat = false;
+                       }

                        // Concat and canonicalize the paths only for
                        // existing scripts that aren't outside ABSPATH
@@ -114,8 +117,17 @@ class WPcom_JS_Concat extends WP_Scripts {

                foreach ( $javascripts as $js_array ) {
                        if ( 'do_item' == $js_array['type'] ) {
-                               if ( $this->do_item( $js_array['handle'], $group ) )
+                               // Disable "concat" for external scripts, otherwise do_item() may print it at the wrong time
+                               if ( in_array( $js_array['handle'], $external_scripts, true ) ) {
+                                       $this->do_concat = false;
+                               }
+                               if ( $this->do_item( $js_array['handle'], $group ) ) {
                                        $this->done[] = $js_array['handle'];
+                               }
+                               // Re-enable "concat"
+                               if ( in_array( $js_array['handle'], $external_scripts, true ) ) {
+                                       $this->do_concat = true;
+                               }
                        } else if ( 'concat' == $js_array['type'] ) {
                                array_map( array( $this, 'print_extra_script' ), $js_array['handles'] );