Prevent skipped items in multiple_source_video_formatter_player field formatter

Synopsis

In the player field formatter a for loop is used to combine all video files into the first delta. This fails for fields with more than 2 items since some items are skipped.

Discussion

In the funtion multi_source_video_field_formatter_view a for loop is used to combine video files from all field deltas into the first delta.

Since the loop end condition is dynamically adjusted, unsetting the copied element in the loop body reduces the item count by one for each iteration. Because the loop index is incremented as well, items will be skipped so the respective files will not be added to the first item.

Actual result

For example, an array of media items such as [0: [a], 1: [b], 2: [c], 3: [d]] will result in the combined item [0: [a, b, d]].

Expected Result

The first delta should end up containing all item's files: [0: [a, b, c, d]].