Fix problem when extending NF. See test/nfloop.

11 files changed, 56 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index d80680f3..84d217da 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2013-09-13         Arnold D. Robbins     <arnold@skeeve.com>
+
+	Fix use of NF after it's extended, e.g. see test/nfloop.awk.
+
+	* awk.h (NULL_FIELD): New flag
+	* builtin.c (do_print_rec): Check f0->flags instead of if
+	equal to Nnull_string.
+	* eval.c (r_get_field): Check (*lhs)->flags instead of if
+	equal to Nnull_string or Null_field.
+	* field.c (init_fields): Init field zero and Null_field with
+	NULL_FIELD flag.
+	(set_NF): Set parse_high_water = NF in case NF extended past the
+	end. This is the actual bug fix.
+
 2013-09-08         Arnold D. Robbins     <arnold@skeeve.com>
 
 	Fixes based on reports from a static code checker. Thanks to
diff --git a/awk.h b/awk.h
index bb2f2054..f57e62e9 100644
--- a/awk.h
+++ b/awk.h
@@ -434,6 +434,7 @@ typedef struct exp_node {
 #		define	MPFN	0x0800       /* arbitrary-precision floating-point number */
 #		define	MPZN	0x1000       /* arbitrary-precision integer */
 #		define	NO_EXT_SET 0x2000    /* extension cannot set a value for this variable */
+#		define	NULL_FIELD 0x4000    /* this is the null field */
 
 /* type = Node_var_array */
 #		define	ARRAYMAXED	0x4000       /* array is at max size */
diff --git a/builtin.c b/builtin.c
index eb823ac1..9258ea60 100644
--- a/builtin.c
+++ b/builtin.c
@@ -2159,7 +2159,7 @@ do_print_rec(int nargs, int redirtype)
 
 	f0 = fields_arr[0];
 
-	if (do_lint && f0 == Nnull_string)
+	if (do_lint && (f0->flags & NULL_FIELD) != 0)
 		lintwarn(_("reference to uninitialized field `$%d'"), 0);
 
 	efwrite(f0->stptr, sizeof(char), f0->stlen, fp, "print", rp, false);
diff --git a/eval.c b/eval.c
index cf2264bf..789832d0 100644
--- a/eval.c
+++ b/eval.c
@@ -1180,7 +1180,7 @@ r_get_field(NODE *n, Func_ptr *assign, bool reference)
 			*assign = reset_record;
 	} else
 		lhs = get_field(field_num, assign);
-	if (do_lint && reference && (*lhs == Null_field || *lhs == Nnull_string))
+	if (do_lint && reference && ((*lhs)->flags & NULL_FIELD) != 0)
 		lintwarn(_("reference to uninitialized field `$%ld'"),
 			      field_num);
 	return lhs;
diff --git a/field.c b/field.c
index 3cd66067..0a7cee8f 100644
--- a/field.c
+++ b/field.c
@@ -85,13 +85,19 @@ void
 init_fields()
 {
 	emalloc(fields_arr, NODE **, sizeof(NODE *), "init_fields");
-	fields_arr[0] = dupnode(Nnull_string);
+
+	getnode(fields_arr[0]);
+	*fields_arr[0] = *Nnull_string;
+	fields_arr[0]->flags |= NULL_FIELD;
+
 	parse_extent = fields_arr[0]->stptr;
 	save_FS = dupnode(FS_node->var_value);
+
 	getnode(Null_field);
 	*Null_field = *Nnull_string;
 	Null_field->valref = 1;
-	Null_field->flags = (FIELD|STRCUR|STRING);
+	Null_field->flags = (FIELD|STRCUR|STRING|NULL_FIELD);
+
 	field0_valid = true;
 }
 
@@ -348,6 +354,7 @@ set_NF()
 			*n = *Null_field;
 			fields_arr[i] = n;
 		}
+		parse_high_water = NF;
 	} else if (parse_high_water > 0) {
 		for (i = NF + 1; i >= 0 && i <= parse_high_water; i++) {
 			unref(fields_arr[i]);
diff --git a/test/ChangeLog b/test/ChangeLog
index 15166f2f..ad0366f2 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -3,6 +3,11 @@
 	* Makefile.am: Fix quoting for generation of Maketests file so
 	that it will happen correctly.
 
+	Unrelated:
+
+	* Makefile.am (nfloop): New test.
+	* nfloop.awk, nfloop.ok: New files.
+
 2013-08-15         Arnold D. Robbins     <arnold@skeeve.com>
 
 	* Makefile.am: Quote $(srcdir) everywhere so that tests can run
diff --git a/test/Makefile.am b/test/Makefile.am
index bbb0354c..8288cf7d 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -540,6 +540,8 @@ EXTRA_DIST = \
 	nfldstr.awk \
 	nfldstr.in \
 	nfldstr.ok \
+	nfloop.awk \
+	nfloop.ok \
 	nfneg.awk \
 	nfneg.ok \
 	nfset.awk \
@@ -943,7 +945,7 @@ BASIC_TESTS = \
 	inputred intest intprec iobug1 \
 	leaddig leadnl litoct longsub longwrds \
 	manglprm math membug1 messages minusstr mmap8k mtchi18n \
-	nasty nasty2 negexp negrange nested nfldstr nfneg nfset nlfldsep \
+	nasty nasty2 negexp negrange nested nfldstr nfloop nfneg nfset nlfldsep \
 	nlinstr nlstrina noeffect nofile nofmtch noloop1 noloop2 nonl \
 	noparms nors nulrsend numindex numsubstr \
 	octsub ofmt ofmta ofmtbig ofmtfidl ofmts ofs1 onlynl opasnidx opasnslf \
diff --git a/test/Makefile.in b/test/Makefile.in
index 959ef3e0..31a22602 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -758,6 +758,8 @@ EXTRA_DIST = \
 	nfldstr.awk \
 	nfldstr.in \
 	nfldstr.ok \
+	nfloop.awk \
+	nfloop.ok \
 	nfneg.awk \
 	nfneg.ok \
 	nfset.awk \
@@ -1160,7 +1162,7 @@ BASIC_TESTS = \
 	inputred intest intprec iobug1 \
 	leaddig leadnl litoct longsub longwrds \
 	manglprm math membug1 messages minusstr mmap8k mtchi18n \
-	nasty nasty2 negexp negrange nested nfldstr nfneg nfset nlfldsep \
+	nasty nasty2 negexp negrange nested nfldstr nfloop nfneg nfset nlfldsep \
 	nlinstr nlstrina noeffect nofile nofmtch noloop1 noloop2 nonl \
 	noparms nors nulrsend numindex numsubstr \
 	octsub ofmt ofmta ofmtbig ofmtfidl ofmts ofs1 onlynl opasnidx opasnslf \
@@ -2721,6 +2723,11 @@ nfldstr:
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  < "$(srcdir)"/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
+nfloop:
+	@echo $@
+	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
+
 nfneg:
 	@echo $@
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/Maketests b/test/Maketests
index 1f3daf76..a1791a92 100644
--- a/test/Maketests
+++ b/test/Maketests
@@ -470,6 +470,11 @@ nfldstr:
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  < "$(srcdir)"/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
+nfloop:
+	@echo $@
+	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
+
 nfneg:
 	@echo $@
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/nfloop.awk b/test/nfloop.awk
new file mode 100644
index 00000000..c37700ac
--- /dev/null
+++ b/test/nfloop.awk
@@ -0,0 +1,8 @@
+BEGIN {
+	$0 = "aaa"
+	NF = 10
+	for (j = 2; j <= NF; ++j) {
+		$j = "_"
+	}
+	print
+}
diff --git a/test/nfloop.ok b/test/nfloop.ok
new file mode 100644
index 00000000..cc683eae
--- /dev/null
+++ b/test/nfloop.ok
@@ -0,0 +1 @@
+aaa _ _ _ _ _ _ _ _ _