bug#45474: Icomplete exhibiting in recursive minibuffer when it shouldn’t

[Juri Linkov]

>> but then later you posted a different patch.  Anyway FWIW here is
>> a safer workable workaround that implements your first suggestion
>> and sets a new explicit buffer-local variable in completing minibuffers,
>> so modes that need to distinguish such minibuffers could check it.
>
> I combined your idea with that of Gregory for the patch below.
> It's far from perfect, but I think it strikes a good balance of
> simplicity, preserving compatibility, and moving in the right direction.
>
> WDYT?

I tested your patch and discovered that it fails when two nested
minibuffers both use completion, e.g. C-x C-f C-h v raises the error:

   Error in post-command-hook (icomplete-post-command-hook): 
(wrong-type-argument symbolp

The value of minibuffer-completion-table is 'read-file-name-internal'
in the C-x C-f minibuffer that is correct.  But the same value is also
in the nested C-h v minibuffer instead of the correct 
help--symbol-completion-table.