bug#20468: Erc timestamps and buffer-invisibility-spec

[Stefan Monnier]

> Is it a bug? Should the default value be (t) instead of t?

Right, now I finally see where the problem was introduced:
the ERC code always starts by calling erc-munge-invisibility-spec, so by
default, the old code ended up setting buffer-invisibility-spec to
`(t)', whereas the new code calls remove-from-invisibility-spec which
ends up not doing anything.

I'm tempted to install the patch below, since I think it makes sense to
expect that remove-from-invisibility-spec makes ELEMENT visible.


        Stefan


diff --git a/lisp/subr.el b/lisp/subr.el
index 9580109..e9a5a2a 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -4172,9 +4173,10 @@ that can be added."
 
 (defun remove-from-invisibility-spec (element)
   "Remove ELEMENT from `buffer-invisibility-spec'."
-  (if (consp buffer-invisibility-spec)
-      (setq buffer-invisibility-spec
-           (delete element buffer-invisibility-spec))))
+  (setq buffer-invisibility-spec
+        (if (consp buffer-invisibility-spec)
+           (delete element buffer-invisibility-spec)
+          (list t))))
 
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