Fix bug in strftime when format argument is an unterminated field string.

9 files changed, 44 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 12f0e5ca..6bc1b339 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2017-01-26         Andrew J. Schorr     <aschorr@telemetry-investments.com>
 
+	* builtin.c (do_strftime): If format argument is passed, we need
+	to terminate it in case it's a field variable.
+
+2017-01-26         Andrew J. Schorr     <aschorr@telemetry-investments.com>
+
 	* node.c (r_format_val): Before we free s->stptr, make sure that it
 	was malloced.
 	(wstr2str): Add comment explaining why it's safe to free n->stptr
diff --git a/builtin.c b/builtin.c
index f71d71dd..0c6cbc01 100644
--- a/builtin.c
+++ b/builtin.c
@@ -1907,6 +1907,7 @@ do_strftime(int nargs)
 	int do_gmt;
 	NODE *val = NULL;
 	NODE *sub = NULL;
+	char save;
 	static const time_t time_t_min = TYPE_MINIMUM(time_t);
 	static const time_t time_t_max = TYPE_MAXIMUM(time_t);
 
@@ -1980,6 +1981,8 @@ do_strftime(int nargs)
 			DEREF(t1);
 			return make_string("", 0);
 		}
+		save = format[formatlen];
+		t1->stptr[formatlen] = '\0';
 	}
 
 	if (do_gmt)
@@ -1987,8 +1990,10 @@ do_strftime(int nargs)
 	else
 		tm = localtime(& fclock);
 
-	if (tm == NULL)
-		return make_string("", 0);
+	if (tm == NULL) {
+		ret = make_string("", 0);
+		goto done;
+	}
 
 	bufp = buf;
 	bufsize = sizeof(buf);
@@ -2014,8 +2019,11 @@ do_strftime(int nargs)
 	ret = make_string(bufp, buflen);
 	if (bufp != buf)
 		efree(bufp);
-	if (t1)
+done:
+	if (t1) {
+		t1->stptr[formatlen] = save;
 		DEREF(t1);
+	}
 	return ret;
 }
 
diff --git a/test/ChangeLog b/test/ChangeLog
index 1b2d4022..badd21b4 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,8 @@
+2017-01-26         Andrew J. Schorr     <aschorr@telemetry-investments.com>
+
+	* Makefile.am (strftfld): New test.
+	* strftfld.awk, strftfld.in, strftfld.ok: New files.
+
 2017-01-15         Andrew J. Schorr     <aschorr@telemetry-investments.com>
 
 	* Makefile.am (concat5): New test.
diff --git a/test/Makefile.am b/test/Makefile.am
index cc9f6d12..1a86825e 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1023,6 +1023,9 @@ EXTRA_DIST = \
 	strftime.awk \
 	strftlng.awk \
 	strftlng.ok \
+	strftfld.awk \
+	strftfld.in \
+	strftfld.ok \
 	strnum1.awk \
 	strnum1.ok \
 	strnum2.awk \
@@ -1228,7 +1231,7 @@ GAWK_EXT_TESTS = \
 	rebuf regnul1 regnul2 regx8bit reginttrad reint reint2 rsgetline rsglstdin rsstart1 \
 	rsstart2 rsstart3 rstest6 shadow shadowbuiltin \
 	sortfor sortfor2 sortu split_after_fpat \
-	splitarg4 strftime \
+	splitarg4 strftime strftfld \
 	strtonum strtonum1 switch2 symtab1 symtab2 symtab3 symtab4 symtab5 symtab6 \
 	symtab7 symtab8 symtab9 symtab10 \
 	typedregex1 typedregex2 typedregex3 typeof1 typeof2 typeof3 typeof4 \
diff --git a/test/Makefile.in b/test/Makefile.in
index a45e26ef..23aedf89 100644
--- a/test/Makefile.in
+++ b/test/Makefile.in
@@ -1281,6 +1281,9 @@ EXTRA_DIST = \
 	strftime.awk \
 	strftlng.awk \
 	strftlng.ok \
+	strftfld.awk \
+	strftfld.in \
+	strftfld.ok \
 	strnum1.awk \
 	strnum1.ok \
 	strnum2.awk \
@@ -1485,7 +1488,7 @@ GAWK_EXT_TESTS = \
 	rebuf regnul1 regnul2 regx8bit reginttrad reint reint2 rsgetline rsglstdin rsstart1 \
 	rsstart2 rsstart3 rstest6 shadow shadowbuiltin \
 	sortfor sortfor2 sortu split_after_fpat \
-	splitarg4 strftime \
+	splitarg4 strftime strftfld \
 	strtonum strtonum1 switch2 symtab1 symtab2 symtab3 symtab4 symtab5 symtab6 \
 	symtab7 symtab8 symtab9 symtab10 \
 	typedregex1 typedregex2 typedregex3 typeof1 typeof2 typeof3 typeof4 \
@@ -4243,6 +4246,11 @@ splitarg4:
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  < "$(srcdir)"/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
+strftfld:
+	@echo $@
+	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  < "$(srcdir)"/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
+
 strtonum:
 	@echo $@
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/Maketests b/test/Maketests
index 5b91af61..82e496de 100644
--- a/test/Maketests
+++ b/test/Maketests
@@ -1442,6 +1442,11 @@ splitarg4:
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  < "$(srcdir)"/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
 	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
 
+strftfld:
+	@echo $@
+	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  < "$(srcdir)"/$@.in >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
+	@-$(CMP) "$(srcdir)"/$@.ok _$@ && rm -f _$@
+
 strtonum:
 	@echo $@
 	@AWKPATH="$(srcdir)" $(AWK) -f $@.awk  >_$@ 2>&1 || echo EXIT CODE: $$? >>_$@
diff --git a/test/strftfld.awk b/test/strftfld.awk
new file mode 100644
index 00000000..26f75a5a
--- /dev/null
+++ b/test/strftfld.awk
@@ -0,0 +1,3 @@
+{
+	print split(strftime($1), f)
+}
diff --git a/test/strftfld.in b/test/strftfld.in
new file mode 100644
index 00000000..c1175143
--- /dev/null
+++ b/test/strftfld.in
@@ -0,0 +1 @@
+%F %T
diff --git a/test/strftfld.ok b/test/strftfld.ok
new file mode 100644
index 00000000..d00491fd
--- /dev/null
+++ b/test/strftfld.ok
@@ -0,0 +1 @@
+1