Re: getopts doesn't update OPTIND when called from function

[Peter Stephenson <p.stephenson@samsung.com>]

On Thu, 28 May 2015 18:18:32 +0200
Martijn Dekker <martijn@inlv.org> wrote:
> I'm writing a shell function that extends the functionality of the
> 'getopts' builtin. For that to work, it is necessary to call the
> 'getopts' builtin from the shell function.
> 
> The POSIX standard specifies that OPTIND and OPTARG are global
> variables, even if the positional parameters are local to the
> function.[*] This makes it possible to call 'getopts' from a function by
> simply passing the global positional parameters along by adding "$@".
> 
> My problem is that zsh does not update the global OPTIND variable when
> getopts is called from a function, which defeats my function on zsh. (It
> does update the global OPTARG variable, though.)

This is documented behaviour (well, sort of -- the documentation didn't
say quite what we actually do) so this needs another compatibility fix.
POSIX_BUILTINS seems appropriate.

diff --git a/Doc/Zsh/builtins.yo b/Doc/Zsh/builtins.yo
index a2c03bc..f8e4edf 100644
--- a/Doc/Zsh/builtins.yo
+++ b/Doc/Zsh/builtins.yo
@@ -866,7 +866,8 @@ vindex(OPTARG, use of)
 
 The first option to be examined may be changed by explicitly assigning
 to tt(OPTIND).  tt(OPTIND) has an initial value of tt(1), and is
-normally reset to tt(1) upon exit from a shell function.  tt(OPTARG)
+normally set to tt(1) upon entry to a shell function and restored
+upon exit (this is disabled by the tt(POSIX_BUILTINS) option).  tt(OPTARG)
 is not reset and retains its value from the most recent call to
 tt(getopts).  If either of tt(OPTIND) or tt(OPTARG) is explicitly
 unset, it remains unset, and the index or option argument is not
diff --git a/Doc/Zsh/options.yo b/Doc/Zsh/options.yo
index 032423d..4c0ae12 100644
--- a/Doc/Zsh/options.yo
+++ b/Doc/Zsh/options.yo
@@ -2038,6 +2038,10 @@ tt(unset).
 In addition, various error conditions associated with the above builtins
 or tt(exec) cause a non-interactive shell to exit and an interactive
 shell to return to its top-level processing.
+
+Furthermore, the tt(getopts) builtin behaves in a POSIX-compatible
+fashion in that the associated variable tt(OPTIND) is not made
+local to functions.
 )
 pindex(POSIX_IDENTIFIERS)
 pindex(NO_POSIX_IDENTIFIERS)
diff --git a/Src/builtin.c b/Src/builtin.c
index a9afb45..18c22f2 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -4713,6 +4713,10 @@ bin_shift(char *name, char **argv, Options ops, UNUSED(int func))
     return ret;
 }
 
+/*
+ * Position of getopts option within OPTIND argument with multiple options.
+ */
+
 /**/
 int optcind;
 
diff --git a/Src/exec.c b/Src/exec.c
index 527d611..9f163a6 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -4910,9 +4910,11 @@ doshfunc(Shfunc shfunc, LinkList doshargs, int noreturnval)
     if (!(flags & PM_UNDEFINED))
 	scriptname = dupstring(name);
     oldzoptind = zoptind;
-    zoptind = 1;
     oldoptcind = optcind;
-    optcind = 0;
+    if (!isset(POSIXBUILTINS)) {
+	zoptind = 1;
+	optcind = 0;
+    }
 
     /* We need to save the current options even if LOCALOPTIONS is *
      * not currently set.  That's because if it gets set in the    *
@@ -5049,8 +5051,10 @@ doshfunc(Shfunc shfunc, LinkList doshargs, int noreturnval)
 	argzero = oargv0;
     }
     pparams = pptab;
-    optcind = oldoptcind;
-    zoptind = oldzoptind;
+    if (!isset(POSIXBUILTINS)) {
+	zoptind = oldzoptind;
+	optcind = oldoptcind;
+    }
     scriptname = oldscriptname;
     oflags = ooflags;