When in Creative mode with the inventory open and any tab* selected, resizing the minecraft window causes the contents of the window to change to what they are under the Search Items tab. The search bar doesn't appear, the visual of which tab is selected stays the same, and the label at the top doesn't change ("Decoration Blocks" etc.), but the area where the actual items appear is the same as if the Search tab were selected - you can take the items and everything. Reopening the inventory, switching tabs, or even clicking on the currently selected tab again returns it to normal.
To replicate, open the creative menu to any tab except for Search Items (and Survival Inventory*) and resize the minecraft window. The contents of the menu will change and can be used like normal.
*This happens consistently with all the "normal" creative tabs (Decoration Blocks, Transportation etc., including Saved Toolbars), but I only saw it happen with the Survival Inventory tab once, and have been unable to replicate it since.
Linked issues
is duplicated by 7
MC-132270
Creative inventory shows ALL items when tabbing out
Resolved
MC-132645
If you resize the game window with an open Creative Inventory, the active tab will show all items
Resolved
MC-133593
Opening or closing the full screen mode or adjusting the size of the window causes the creation mode item bar to display "search" items (not consistent with the items and contents that are displayed)
Resolved
MC-133736
Creative tabs lose sorting when switching fullscreen mode
Resolved
MC-133952
Entering/Exiting fullscreen while in the inventory causes problems
Resolved
Confirmed for MC 1.13-pre4.Probably this happens because when you resize the window, the game "resets" the content of the menu (setting it to the default one), but not the tab.