diff --git a/ChangeLog b/ChangeLog
index 17715fc..59d4b07 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-08-29         Arnold D. Robbins     <arnold@skeeve.com>
+
+	* REGRESS: Check for existence of a.out. If not there, run
+	make.  Enable core dumps for T.arnold system status test
+	to work on MacOS X.
+
 2018-08-22         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* awktest.tar (testdir/T.expr): Fix test for unary plus.
diff --git a/FIXES b/FIXES
index d414c6d..909afb7 100644
--- a/FIXES
+++ b/FIXES
@@ -25,6 +25,11 @@ THIS SOFTWARE.
 This file lists all bug fixes, changes, etc., made since the AWK book
 was sent to the printers in August, 1987.
 
+Oct 25, 2018:
+	Added test in maketab.c to prevent generating a proctab entry
+	for YYSTYPE_IS_DEFINED.  It was harmless but some gcc settings
+	generated a warning message.  Thanks to Nan Xiao for report.
+
 Aug 27, 2018:
 	Disallow '$' in printf formats; arguments evaluated in order
 	and printed in order.
diff --git a/REGRESS b/REGRESS
index facbd83..7d3ded6 100755
--- a/REGRESS
+++ b/REGRESS
@@ -1,5 +1,15 @@
 #! /bin/sh
 
+case `uname` in
+CYGWIN)	EXE=a.exe ;;
+*)	EXE=a.out ;;
+esac
+
+if [ ! -f $EXE ]
+then
+	make || exit 1
+fi
+
 if [ -d testdir ]
 then
 	true	# do nothing
@@ -16,5 +26,10 @@ cd testdir
 pwd
 PATH=.:$PATH
 export PATH
+if (ulimit -c unlimited > /dev/null 2>&1)
+then
+	# Workaround broken default on MacOS X
+	ulimit -c unlimited
+fi
 
 REGRESS
diff --git a/bugs-fixed/README b/bugs-fixed/README
index 6d6203f..4656e3e 100644
--- a/bugs-fixed/README
+++ b/bugs-fixed/README
@@ -24,9 +24,17 @@ and also if CONVFMT changed.
 7. unary-plus: Unary plus on a string constant returned the string.
 Instead, it should convert the value to numeric and give that value.
 
-X. numeric-subsep, numeric-fs, numeric-output-seps, numerics-rs: If SUBSEP,
+8. missing-precision: When using the format string "%*s", the precision
+argument was used without checking if it was present first.
+
+9. fmt-overflow: The buffer used for OFMT/CONVFMT conversions was written
+to with sprintf(), which meant that some conversions could write past the
+end.
+
+10. numeric-subsep, numeric-fs, numeric-output-seps, numerics-rs: If SUBSEP,
 FS, RS, OFS, or ORS were set to a numeric value, then their string values
 wouldn't always be generated before being needed.
 
-X. subsep-overflow: The length of SUBSEP needs to be rechecked after
+11. subsep-overflow: The length of SUBSEP needs to be rechecked after
 calling execute(), in case SUBSEP itself has been changed.
+
diff --git a/bugs-fixed/fmt-overflow.awk b/bugs-fixed/fmt-overflow.awk
new file mode 100644
index 0000000..bf5877e
--- /dev/null
+++ b/bugs-fixed/fmt-overflow.awk
@@ -0,0 +1 @@
+BEGIN { OFMT = "%.1000f"; print 1.25; }
diff --git a/bugs-fixed/fmt-overflow.ok b/bugs-fixed/fmt-overflow.ok
new file mode 100644
index 0000000..5f7449e
--- /dev/null
+++ b/bugs-fixed/fmt-overflow.ok
@@ -0,0 +1 @@
+1.2500000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
diff --git a/bugs-fixed/missing-precision.awk b/bugs-fixed/missing-precision.awk
new file mode 100644
index 0000000..4e7a74b
--- /dev/null
+++ b/bugs-fixed/missing-precision.awk
@@ -0,0 +1 @@
+BEGIN { printf("%*s"); }
diff --git a/bugs-fixed/missing-precision.ok b/bugs-fixed/missing-precision.ok
new file mode 100644
index 0000000..608b4fa
--- /dev/null
+++ b/bugs-fixed/missing-precision.ok
@@ -0,0 +1,2 @@
+./a.out: not enough args in printf(%*s)
+ source line number 1
diff --git a/makefile b/makefile
index ae80e4d..e0a43da 100644
--- a/makefile
+++ b/makefile
@@ -34,8 +34,8 @@ CC = gcc -g -Wall -pedantic
 
 # yacc options.  pick one; this varies a lot by system.
 #YFLAGS = -d -S
-#YACC = bison -d -y
-YACC = yacc -d
+YACC = bison -d -y
+#YACC = yacc -d
 #		-S uses sprintf in yacc parser instead of sprint
 
 OFILES = b.o main.o parse.o proctab.o tran.o lib.o run.o lex.o
diff --git a/maketab.c b/maketab.c
index e23974c..bb8e317 100644
--- a/maketab.c
+++ b/maketab.c
@@ -135,6 +135,8 @@ int main(int argc, char *argv[])
 		n = sscanf(buf, "%1c %s %s %d", &c, def, name, &tok);
 		if (c != '#' || (n != 4 && strcmp(def,"define") != 0))	/* not a valid #define */
 			continue;
+		if (strcmp(name, "YYSTYPE_IS_DECLARED") == 0)
+			continue;
 		if (tok < FIRSTTOKEN || tok > LASTTOKEN) {
 			/* fprintf(stderr, "maketab funny token %d %s ignored\n", tok, buf); */
 			continue;
diff --git a/run.c b/run.c
index ac354e2..96743f7 100644
--- a/run.c
+++ b/run.c
@@ -866,6 +866,9 @@ int format(char **pbuf, int *pbufsize, const char *s, Node *a)	/* printf-like co
 				FATAL("'$' not permitted in awk formats");
 			}
 			if (*s == '*') {
+				if (a == NULL) {
+					FATAL("not enough args in printf(%s)", os);
+				}
 				x = execute(a);
 				a = a->nnext;
 				sprintf(t-1, "%d", fmtwd=(int) getfval(x));
diff --git a/tran.c b/tran.c
index f4a134b..d1dfe2b 100644
--- a/tran.c
+++ b/tran.c
@@ -406,7 +406,7 @@ Awkfloat getfval(Cell *vp)	/* get float val of a Cell */
 
 static char *get_str_val(Cell *vp, char **fmt)        /* get string val of a Cell */
 {
-	char s[100];	/* BUG: unchecked */
+	char s[256];
 	double dtemp;
 
 	if ((vp->tval & (NUM | STR)) == 0)
@@ -445,9 +445,9 @@ static char *get_str_val(Cell *vp, char **fmt)        /* get string val of a Cel
 		if (freeable(vp)) \
 			xfree(vp->sval); \
 		if (modf(vp->fval, &dtemp) == 0)	/* it's integral */ \
-			sprintf(s, "%.30g", vp->fval); \
+			snprintf(s, sizeof (s), "%.30g", vp->fval); \
 		else \
-			sprintf(s, *fmt, vp->fval); \
+			snprintf(s, sizeof (s), *fmt, vp->fval); \
 		vp->sval = tostring(s); \
 		vp->tval &= ~DONTFREE; \
 		vp->tval |= STR; \