Subject: Re: [bug] shwordsplit not working on $@ when $# > 1
From: Bart Schaefer <[email-masked]>
To: [email-masked]
Date: Wed, 10 Aug 2016 17:39:35 -0700
List-Id: Zsh Workers List <zsh-workers.zsh.org>

On Aug 10,  1:56pm, Peter Stephenson wrote:
} Subject: Re: [bug] shwordsplit not working on $@ when $# > 1
}
} > Existing tests still pass, but then they always did, this needs a
} > new one.  Holding off until we think of other edge cases.
} 
} This tests the significant cases with $@.

OK, this replaces both workers/39009 and workers/39013 -- to the latter
it adds three more tests based on workers/39018.  I also re-ordered the
statements in the 39013 tests to make it obvious that IFS doesn't have
an effect on the "set -- ..." statements.

diff --git a/Src/subst.c b/Src/subst.c
index e3af156..ae3e4c4 100644
--- a/Src/subst.c
+++ b/Src/subst.c
@@ -3454,13 +3454,22 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
      * exception is that ${name:-word} and ${name:+word} will have already
      * done any requested splitting of the word value with quoting preserved.
      */
-    if (ssub || (spbreak && isarr >= 0) || spsep || sep) {
+    if (ssub || spbreak || spsep || sep) {
+	int force_split = !ssub && (spbreak || spsep);
 	if (isarr) {
-	    val = sepjoin(aval, sep, 1);
-	    isarr = 0;
-	    ms_flags = 0;
+	    if (nojoin == 0) {
+		val = sepjoin(aval, sep, 1);
+		isarr = 0;
+		ms_flags = 0;
+	    } else if (force_split && nojoin == 2) {
+		/* Hack to simulate splitting individual elements:
+		 * first join on what we later use to split
+		 */
+		val = sepjoin(aval, spsep, 1);
+		isarr = 0;
+	    }
 	}
-	if (!ssub && (spbreak || spsep)) {
+	if (force_split && !isarr) {
 	    aval = sepsplit(val, spsep, 0, 1);
 	    if (!aval || !aval[0])
 		val = dupstring("");
@@ -3527,7 +3536,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	}
 	/*
 	 * TODO:  It would be really quite nice to abstract the
-	 * isarr and !issarr code into a function which gets
+	 * isarr and !isarr code into a function which gets
 	 * passed a pointer to a function with the effect of
 	 * the promptexpand bit.  Then we could use this for
 	 * a lot of stuff and bury val/aval/isarr inside a structure
diff --git a/Test/D04parameter.ztst b/Test/D04parameter.ztst
index 7cb297e..35630c5 100644
--- a/Test/D04parameter.ztst
+++ b/Test/D04parameter.ztst
@@ -1920,3 +1920,58 @@
   print $array
 0:"-" works after "[" in same expression (Dash problem)
 >foo two three
+
+  (
+  setopt shwordsplit
+  set -- whim:wham:whom
+  IFS=:
+  print -l $@
+  )
+0:Splitting of $@ on IFS: single element
+>whim
+>wham
+>whom
+
+  (
+  setopt shwordsplit
+  set -- one:two bucklemy:shoe
+  IFS=:
+  print -l $@
+  )
+0:Splitting of $@ on IFS: multiple elements
+# No forced joining in this case
+>one
+>two
+>bucklemy
+>shoe
+
+  (
+  set -- one:two bucklemy:shoe
+  print -l ${(s.:.)@}
+  )
+0:Splitting of $@ on (s): multiple elements
+# Forced joining in this case
+>one
+>two bucklemy
+>shoe
+
+  (
+  set -- one:two bucklemy:shoe
+  print -l ${(@s.:.)@}
+  )
+0:Splitting of $@ on (@s): multiple elements
+# Forced non-joining in this case
+>one
+>two
+>bucklemy
+>shoe
+
+  (
+  set -- one:two bucklemy:shoe
+  IFS=
+  setopt shwordsplit
+  print -l ${@}
+  )
+0:Joining of $@ does not happen when IFS is empty
+>one:two
+>bucklemy:shoe