From be1662dd1556151e204fd9db9fda327bb0393ae1 Mon Sep 17 00:00:00 2001
From: George Koehler <kernigh@gmail.com>
Date: Wed, 30 Oct 2019 16:53:09 -0400
Subject: [PATCH] Change the optional parameter of n_coerc() to a pointer

Fixes https://github.com/davidgiven/ack/issues/188

One call to n_coerc() omits the 6th and last argument.  This worked in
traditional K&R C, but stops working if we declare n_coerc() with a
prototype of all 6 parameters.

Change the last parameter to a pointer.  Declare n_coerc() with
prototype, so it now requires all 6 arguments.  Pass NULL when have no
iocc_t.  This NULL exists only to satisfy the prototype; n_coerc()
will not use this NULL.

A different fix would declare n_coerc() with 5 parameters and `...`,
then use <stdarg.h> to read the 6th argument when it exists.
---
 util/ncgg/cgg.y   | 4 ++--
 util/ncgg/coerc.c | 6 +++---
 util/ncgg/coerc.h | 3 +--
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/util/ncgg/cgg.y b/util/ncgg/cgg.y
index c648d276c..0c0e16514 100644
--- a/util/ncgg/cgg.y
+++ b/util/ncgg/cgg.y
@@ -607,7 +607,7 @@ coercdeflist_el
 		{startline = lineno; tokpatlen=0; inithall();}
 	  STACK allocates generates YIELDS tokeninstance
 		{ checkhall();
-		  n_coerc(0,0,$4,$5,(struct varinfo *) 0,$7);
+		  n_coerc(0,0,$4,$5,NULL,&$7);
 		  freevi($4);
 		  freevi($5);
 		}
@@ -623,7 +623,7 @@ coercdeflist_el
 	  optexpr allocates generates yields
 	  	{ tokpatro[0] = 0;
 		  checkhall();
-		  n_coerc($3,$5,$6,$7,$8);
+		  n_coerc($3,$5,$6,$7,$8,NULL);
 		  freevi($6);
 		  freevi($7);
 		  cursetno = -1;
diff --git a/util/ncgg/coerc.c b/util/ncgg/coerc.c
index 23b711b22..50265c59e 100644
--- a/util/ncgg/coerc.c
+++ b/util/ncgg/coerc.c
@@ -208,7 +208,7 @@ set_t unstackset;
 
 /*VARARGS5*/
 
-void n_coerc(int ti, int be, struct varinfo *al, struct varinfo *ge, struct varinfo *rp, iocc_t in)
+void n_coerc(int ti, int be, struct varinfo *al, struct varinfo *ge, struct varinfo *rp, iocc_p inp)
 {
 	register c3_p c3p;
 	register int i;
@@ -236,7 +236,7 @@ void n_coerc(int ti, int be, struct varinfo *al, struct varinfo *ge, struct vari
 	{
 		NEW(rp, struct varinfo);
 		rp->vi_next = 0;
-		rp->vi_int[0] = in.in_index;
+		rp->vi_int[0] = inp->in_index;
 	}
 	if (nallreg > 1)
 		error("More than 1 register may not be allocated");
@@ -250,7 +250,7 @@ void n_coerc(int ti, int be, struct varinfo *al, struct varinfo *ge, struct vari
 	dopattern(ti == 0, VI_NULL, al, ge, rp, VI_NULL);
 	if (ti == 0)
 		for (i = 0; i < SETSIZE; i++)
-			unstackset.set_val[i] |= in.in_set[i];
+			unstackset.set_val[i] |= inp->in_set[i];
 	freevi(rp);
 }
 
diff --git a/util/ncgg/coerc.h b/util/ncgg/coerc.h
index b34338e2f..e45c75754 100644
--- a/util/ncgg/coerc.h
+++ b/util/ncgg/coerc.h
@@ -23,8 +23,7 @@ struct varinfo *gen_preturn(void);
 struct varinfo *gen_tlab(int n);
 void n_stack(int s, int e, int p, struct varinfo *vi);
 void checkstacking(register short *sp);
-/* cgg.y is buggy!!! it has one less parameter.. */
-/*void n_coerc(int ti, int be, struct varinfo *al, struct varinfo *ge, struct varinfo *rp, iocc_t in);*/
+void n_coerc(int ti, int be, struct varinfo *al, struct varinfo *ge, struct varinfo *rp, iocc_p inp);
 void checkunstacking(int setno);
 
 #endif /* COERC_H_ */