Fix bug with FPAT.

10 files changed, 54 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 3ac63786..5fcf749c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -33,6 +33,12 @@
 
 	* field.c (set_FIELDWIDTHS): Adjust calculations.
 
+	Fix problem with FPAT, reported by "T. X. G." <leopardie333@yahoo.com>
+
+	* awk.h (Regexp): Add new member 'non_empty'.
+	* field.c (fpat_parse_field): Save/restore local variable non_empty
+	from member in Regexp struct.
+
 2011-08-09         Arnold D. Robbins     <arnold@skeeve.com>
 
 	Fix pty issue reported by "T. X. G." <leopardie333@yahoo.com>
diff --git a/awk.h b/awk.h
index 4b4210f0..2ffe91d9 100644
--- a/awk.h
+++ b/awk.h
@@ -205,6 +205,7 @@ typedef struct Regexp {
 	struct dfa *dfareg;
 	short dfa;
 	short has_anchor;	/* speed up of avoid_dfa kludge, temporary */
+	short non_empty;	/* for use in fpat_parse_field */
 } Regexp;
 #define	RESTART(rp,s)	(rp)->regs.start[0]
 #define	REEND(rp,s)	(rp)->regs.end[0]
diff --git a/field.c b/field.c
index 148f8f0b..14a03332 100644
--- a/field.c
+++ b/field.c
@@ -849,7 +849,8 @@ get_field(long requested, Func_ptr *assign)
 	if (assign != NULL)
 		field0_valid = FALSE;		/* $0 needs reconstruction */
 #else
-	/* keep things uniform. Also, mere intention of assigning something
+	/*
+	 * Keep things uniform. Also, mere intention of assigning something
 	 * to $n should not make $0 invalid. Makes sense to invalidate $0
 	 * after the actual assignment is performed. Not a real issue in 
 	 * the interpreter otherwise, but causes problem in the
@@ -1584,9 +1585,6 @@ fpat_parse_field(long up_to,	/* parse only up to this field number */
 		memset(&mbs, 0, sizeof(mbstate_t));
 #endif
 
-	if (in_middle)
-		regex_flags |= RE_NO_BOL;
-
 	if (up_to == UNLIMITED)
 		nf = 0;
 
@@ -1596,7 +1594,13 @@ fpat_parse_field(long up_to,	/* parse only up to this field number */
 	if (rp == NULL) /* use FPAT */
 		rp = FPAT_regexp;
 
-	eosflag = non_empty = FALSE;
+	if (in_middle) {
+		regex_flags |= RE_NO_BOL;
+		non_empty = rp->non_empty;
+	} else
+		non_empty = FALSE;
+
+	eosflag = FALSE;
 	need_to_set_sep = TRUE;
 	start = scan;
 	while (research(rp, scan, 0, (end - scan), regex_flags) != -1
@@ -1675,5 +1679,6 @@ fpat_parse_field(long up_to,	/* parse only up to this field number */
 	}
 
 	*buf = scan;
+	rp->non_empty = non_empty;
 	return nf;
 }
diff --git a/test/ChangeLog b/test/ChangeLog
index 334f1961..8c165b04 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,7 +1,8 @@
 2011-08-10         Arnold D. Robbins     <arnold@skeeve.com>
 
-	* Makefile.am (beginfile2, fwtest3): New tests.
+	* Makefile.am (beginfile2, fpat3, fwtest3): New tests.
 	* beginfile2.awk, beginfile2.in, beginfile2.ok: New files.
+	* fpat3.awk, fpat3.in, fpat3.ok: New files.
 	* fwtest3.awk, fwtest3.in, fwtest3.ok: New files.
 
 2011-08-09         Arnold D. Robbins     <arnold@skeeve.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index a7789953..3d259afe 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -234,6 +234,9 @@ EXTRA_DIST = \
 	fpat1.ok \
 	fpat2.awk \
 	fpat2.ok \
+	fpat3.awk \
+	fpat3.in \
+	fpat3.ok \
 	fpatnull.awk \
 	fpatnull.in \
 	fpatnull.ok \
@@ -811,7 +814,8 @@ GAWK_EXT_TESTS = \
 	aadelete1 aadelete2 aarray1 aasort aasorti argtest arraysort \
 	backw badargs beginfile1 beginfile2 \
 	binmode1 clos1way delsub devfd devfd1 \
-	devfd2 dumpvars exit fieldwdth fpat1 fpat2 fpatnull fsfwfs funlen \
+	devfd2 dumpvars exit fieldwdth fpat1 fpat2 fpat3 \
+	fpatnull fsfwfs funlen \
 	fwtest fwtest2 fwtest3 \
 	gensub gensub2 getlndir gnuops2 gnuops3 gnureops \
 	icasefs icasers igncdym igncfs ignrcas2 ignrcase indirectcall lint \
diff --git a/test/Makefile.in b/test/Makefile.in
index 1f1f5820..3dd318f9 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -419,6 +419,9 @@ EXTRA_DIST = \
 	fpat1.ok \
 	fpat2.awk \
 	fpat2.ok \
+	fpat3.awk \
+	fpat3.in \
+	fpat3.ok \
 	fpatnull.awk \
 	fpatnull.in \
 	fpatnull.ok \
@@ -996,7 +999,8 @@ GAWK_EXT_TESTS = \
 	aadelete1 aadelete2 aarray1 aasort aasorti argtest arraysort \
 	backw badargs beginfile1 beginfile2 \
 	binmode1 clos1way delsub devfd devfd1 \
-	devfd2 dumpvars exit fieldwdth fpat1 fpat2 fpatnull fsfwfs funlen \
+	devfd2 dumpvars exit fieldwdth fpat1 fpat2 fpat3 \
+	fpatnull fsfwfs funlen \
 	fwtest fwtest2 fwtest3 \
 	gensub gensub2 getlndir gnuops2 gnuops3 gnureops \
 	icasefs icasers igncdym igncfs ignrcas2 ignrcase indirectcall lint \
@@ -2689,6 +2693,11 @@ fpat2:
 	@AWKPATH=$(srcdir) $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) $(srcdir)/$@.ok _$@ && rm -f _$@
 
+fpat3:
+	@echo fpat3
+	@AWKPATH=$(srcdir) $(AWK) -f $@.awk  < $(srcdir)/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) $(srcdir)/$@.ok _$@ && rm -f _$@
+
 fpatnull:
 	@echo fpatnull
 	@AWKPATH=$(srcdir) $(AWK) -f $@.awk  < $(srcdir)/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/Maketests b/test/Maketests
index cfbfc79e..c76769f4 100644
--- a/test/Maketests
+++ b/test/Maketests
@@ -930,6 +930,11 @@ fpat2:
 	@AWKPATH=$(srcdir) $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) $(srcdir)/$@.ok _$@ && rm -f _$@
 
+fpat3:
+	@echo fpat3
+	@AWKPATH=$(srcdir) $(AWK) -f $@.awk  < $(srcdir)/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) $(srcdir)/$@.ok _$@ && rm -f _$@
+
 fpatnull:
 	@echo fpatnull
 	@AWKPATH=$(srcdir) $(AWK) -f $@.awk  < $(srcdir)/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/fpat3.awk b/test/fpat3.awk
new file mode 100644
index 00000000..801bb58e
--- /dev/null
+++ b/test/fpat3.awk
@@ -0,0 +1,10 @@
+BEGIN {
+	FPAT = "[^,]*"
+
+}
+
+{
+	if (x) NF
+	for (i = 1; i <= 4; ++i)
+		print i, $i
+}
diff --git a/test/fpat3.in b/test/fpat3.in
new file mode 100644
index 00000000..28416a42
--- /dev/null
+++ b/test/fpat3.in
@@ -0,0 +1 @@
+a,b,,c
diff --git a/test/fpat3.ok b/test/fpat3.ok
new file mode 100644
index 00000000..543bb429
--- /dev/null
+++ b/test/fpat3.ok
@@ -0,0 +1,4 @@
+1 a
+2 b
+3 
+4 c