patch 8.2.3743: ":sign" can add a highlight group without a name Commit: https://github.com/vim/vim/commit/5e18ccc60bdddc4aa39ab039f1a7c918f29e67ce Author: Bram Moolenaar <Bram@vim.org> Date: Sun Dec 5 13:02:50 2021 +0000 patch 8.2.3743: ":sign" can add a highlight group without a name Problem: ":sign" can add a highlight group without a name. Solution: Give an error if the group name is missing. (closes https://github.com/vim/vim/issues/9280)

| +0#af5f00255#ffffff0@1|1| |1+0#0000000&@4| @65
| +0#af5f00255&@1|2| |1+0#0000000&@3|2| @65
| +8#af5f00255&@1|3| >1+0#0000000&@3|3| @65
| +0#af5f00255&@1|4| |1+0#0000000&@3|4| @65
| +0#af5f00255&@1|5| |1+0#0000000&@3|5| @65
| +0#af5f00255&@1|6| |1+0#0000000&@3|6| @65
| +0#af5f00255&@1|7| |1+0#0000000&@3|7| @65
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