Description

Fix the drag-and-drop import overlay being incorrectly activated on Chromium-based browsers (Chrome, Edge, Brave, Opera) when users drag internal page elements such as the phpMyAdmin logo, icons, or links. Firefox is not affected because it does not expose Files in dataTransfer.types for in-page drags.

Changes (single file: js/src/drag_drop_import.js)

1. New internalDomDrag flag (property)

Added a boolean property internalDomDrag to the DragDropImport object.
Tracks whether the current drag operation was initiated from within the page DOM (i.e., user dragged a page element, not an OS file).

2. New markInternalDrag(event) method

Bound to the dragstart event on document.
Since OS file drags never trigger dragstart on the page, this reliably distinguishes internal DOM drags from external file drags.

3. New clearInternalDrag() method

Resets internalDomDrag to false.
Bound to dragend and drop events to ensure the flag is always cleaned up.

4. Rewritten hasFiles(event) method (core fix)

The original one-liner:

return !(typeof event.originalEvent.dataTransfer.types === 'undefined' ||
    $.inArray('Files', event.originalEvent.dataTransfer.types) < 0 ||
    $.inArray('application/x-moz-nativeimage', event.originalEvent.dataTransfer.types) >= 0);

was replaced with a multi-layered detection approach:

• Internal DOM drag check: If internalDomDrag is true, returns false immediately
• **undefined** types guard: Returns false when dataTransfer.types is undefined.
• Files type presence: Returns false if Files is not in the types list.
• Firefox native image exclusion: Returns false if application/x-moz-nativeimage is present (retained from original logic).
• Chromium internal element heuristic (new): Returns false if text/uri-list or text/html are present — these accompany in-page element drags on Chromium but are absent when dragging real OS files.

5. Updated drop(event) handler

Added an early hasFiles() guard at the top of the drop handler to reject non-file drops cleanly.
Added clearInternalDrag() call at the end of the handler to reset state.

6. New event listeners

$(document).on('dragstart', DragDropImport.markInternalDrag);
$(document).on('dragend drop', DragDropImport.clearInternalDrag);

Fixes #18557

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Demo