OS-7315 Update nawk(1) field splitting behaviour to match POSIX defin…

…ition

Reviewed by: Robert Mustacchi <rm@joyent.com>
Approved by: Jason King <jbk@joyent.com>

usr/src/cmd/awk/awk.h

@@ -338,6 +338,7 @@ extern	void	FATAL(const char *, ...) __attribute__((__noreturn__));
 extern	void	WARNING(const char *, ...);
 extern	void	error(void);
 extern	void	nextfile(void);
+extern	void	savefs(void);
 
 extern	int	isclvar(const char *);
 extern	int	is_number(const char *);

usr/src/cmd/awk/lib.c

@@ -144,6 +144,23 @@ initgetrec(void)
 	infile = stdin;		/* no filenames, so use stdin */
 }
 
+/*
+ * POSIX specifies that fields are supposed to be evaluated as if they were
+ * split using the value of FS at the time that the record's value ($0) was
+ * read.
+ *
+ * Since field-splitting is done lazily, we save the current value of FS
+ * whenever a new record is read in (implicitly or via getline), or when
+ * a new value is assigned to $0.
+ */
+void
+savefs(void)
+{
+	if (strlen(getsval(fsloc)) >= sizeof (inputFS))
+		FATAL("field separator %.10s... is too long", *FS);
+	(void) strcpy(inputFS, *FS);
+}
+
 static int firsttime = 1;
 
 /*
@@ -167,6 +184,7 @@ getrec(char **pbuf, size_t *pbufsize, int isrecord)
 	if (isrecord) {
 		donefld = 0;
 		donerec = 1;
+		savefs();
 	}
 	saveb0 = buf[0];
 	buf[0] = '\0';
@@ -242,9 +260,6 @@ readrec(char **pbuf, size_t *pbufsize, FILE *inf)	/* read one record into buf */
 	size_t bufsize = *pbufsize;
 	char *rs = getsval(rsloc);
 
-	if (strlen(getsval(fsloc)) >= sizeof (inputFS))
-		FATAL("field separator %.10s... is too long", *FS);
-	(void) strcpy(inputFS, *FS);	/* for subsequent field splitting */
 	if ((sep = *rs) == 0) {
 		sep = '\n';
 		/* skip leading \n's */
@@ -342,9 +357,6 @@ fldbld(void)	/* create fields from current record */
 	fr = fields;
 
 	i = 0;	/* number of fields accumulated here */
-	if (strlen(getsval(fsloc)) >= sizeof (inputFS))
-		FATAL("field separator %.10s... is too long", *FS);
-	(void) strcpy(inputFS, *FS);
 	if (strlen(inputFS) > 1) {	/* it's a regular expression */
 		i = refldbld(r, inputFS);
 	} else if ((sep = *inputFS) == ' ') {	/* default whitespace */

usr/src/cmd/awk/tran.c

@@ -377,6 +377,7 @@ setfval(Cell *vp, Awkfloat f)	/* set float val of a Cell */
 	} else if (isrec(vp)) {
 		donefld = 0;	/* mark $1... invalid */
 		donerec = 1;
+		savefs();
 	} else if (vp == ofsloc) {
 		if (donerec == 0)
 			recbld();
@@ -424,6 +425,7 @@ setsval(Cell *vp, const char *s)	/* set string val of a Cell */
 	} else if (isrec(vp)) {
 		donefld = 0;	/* mark $1... invalid */
 		donerec = 1;
+		savefs();
 	} else if (vp == ofsloc) {
 		if (donerec == 0)
 			recbld();

usr/src/test/util-tests/tests/awk/bugs-fixed/fs-overflow.ok

@@ -1,3 +1,3 @@
 $AWK: field separator cccccccccc... is too long
- source line number 12
+ source line number 11
 EXIT CODE: 2

usr/src/test/util-tests/tests/awk/tests/T.split

@@ -18,14 +18,31 @@ fail() {
 
 echo T.split: misc tests of field splitting and split command
 
-echo a:bc:def > $TEMP0
-echo a > $TEMP1
-$AWK '{ FS = ":"; print $1 }' $TEMP0 > $TEMP2
+$AWK 'BEGIN {
+	# Assign string to $0, then change FS.
+	FS = ":";
+	$0="a:bc:def";
+	FS = "-";
+	print FS, $1, NF;
+
+	# Assign number to $0, then change FS.
+	FS = "2";
+	$0=1212121;
+	FS="3";
+	print FS, $1, NF;
+}' > $TEMP1
+echo '- a 3
+3 1 4' > $TEMP2
 diff $TEMP1 $TEMP2 || fail 'BAD: T.split 0.1'
 
-echo a:bc:def > $TEMP0
-echo 3 > $TEMP1
-$AWK '{ FS = ":"; print NF }' $TEMP0 > $TEMP2
+$AWK 'BEGIN {
+	# FS changes after getline.
+	FS = ":";
+	"echo a:bc:def" | getline;
+	FS = "-";
+	print FS, $1, NF;
+}' > $TEMP1
+echo '- a 3' > $TEMP2
 diff $TEMP1 $TEMP2 || fail 'BAD: T.split 0.2'
 
 echo '
@@ -45,6 +62,52 @@ echo '0
 4' > $TEMP2
 diff $TEMP1 $TEMP2 || fail 'BAD: T.split 0.3'
 
+# getline var shouldn't impact fields.
+
+echo 'f b a' > $TEMP0
+$AWK '{
+	FS = ":";
+	getline a < "/etc/passwd";
+	print $1;
+}' $TEMP0 > $TEMP1
+echo 'f' > $TEMP2
+diff $TEMP1 $TEMP2 || fail 'BAD: T.split 0.4'
+
+echo 'a b c d
+foo
+e f g h i
+bar' > $TEMP0
+$AWK '{
+	FS=":";
+	getline v;
+	print $2, NF;
+	FS=" ";
+}' $TEMP0 > $TEMP1
+echo 'b 4
+f 5' > $TEMP2
+diff $TEMP1 $TEMP2 || fail 'BAD: T.split 0.5'
+
+echo 'a.b.c=d.e.f
+g.h.i=j.k.l
+m.n.o=p.q.r' > $TEMP0
+echo 'b
+h
+n' > $TEMP1
+$AWK 'BEGIN { FS="=" } { FS="."; $0=$1; print $2; FS="="; }' $TEMP0 > $TEMP2
+diff $TEMP1 $TEMP2 || fail 'BAD: T.split (record assignment 1)'
+
+echo 'a.b.c=d.e.f
+g.h.i=j.k.l
+m.n.o=p.q.r' > $TEMP0
+echo 'd.e.f
+b
+j.k.l
+h
+p.q.r
+n' > $TEMP1
+$AWK 'BEGIN { FS="=" } { print $2; FS="."; $0=$1; print $2; FS="="; }' $TEMP0 > $TEMP2
+diff $TEMP1 $TEMP2 || fail 'BAD: T.split (record assignment 2)'
+
 echo 'abc
 de
 f