Re: [PATCH] _arguments: Escape colons and backslashes in $opt_args unambiguously.

[Daniel Shahaf <d.s@daniel.shahaf.name>]

Bart Schaefer wrote on Wed, Sep 07, 2016 at 17:13:56 -0700:
> I suspect "ag" is the same thing I have installed as "ack".

"ag" and "ack" are distinct tools.

Applied both of your suggestions, and added a paragraph:

diff --git a/Doc/Zsh/compsys.yo b/Doc/Zsh/compsys.yo
index b2cc392..ecf17e7 100644
--- a/Doc/Zsh/compsys.yo
+++ b/Doc/Zsh/compsys.yo
@@ -3949,9 +3949,7 @@ arguments.  Options are stored in the associative array
 `tt(opt_args)' with option names as keys and their arguments as
 the values.  For options that have more than one argument these are
 given as one string, separated by colons.  All colons and backslashes
-in the original arguments are preceded with backslashes.  (Note:
-Zsh 5.2 and older did not escape backslashes in the original string;
-see the tt(NEWS) file for details.)
+in the original arguments are preceded with backslashes.
 
 The parameter `tt(context)' is set when returning to the calling function
 to perform an action of the form `tt(->)var(string)'.  It is set to an
diff --git a/README b/README
index 019294e..d92fb61 100644
--- a/README
+++ b/README
@@ -91,10 +91,15 @@ equivalent of "*(1)") as well as many other forms.
 and colons in the values of option arguments when populating the $opt_args
 associative array.  Previously, colons were escaped with a backslash but
 backslashes were not themselves escaped with a backslash, which lead to
-ambiguity: if the -x option took two arguments (as in
+ambiguity: '-x foo\:bar' (one argument with a backslashed colon) and
+'-x foo\\ bar' (two argumnets, and the first one ends in a backslash) would
+both set $opt_args[-x] to the same value.  This example assumes the -x
+option's spec declared two arguments, as in:
     _arguments : -x:foo:${action}:bar:$action
-), it would be impossible to tell from $opt_args whether the command-line
-was '-x foo\:bar' or '-x foo\\ bar'.
+
+For the more common case of non-repeatable options that take a single
+argument, completion functions now have to unescape not only colons but
+also backslashes when obtaining the option's argument from $opt_args.
 
 Incompatibilities between 5.0.8 and 5.2
 ---------------------------------------