From 98ef6a8510d555148528e4fffb6cfa587dbd4c46 Mon Sep 17 00:00:00 2001
From: Tomasz Kramkowski <tk@the-tk.com>
Date: Sat, 7 Aug 2021 15:10:44 +0100
Subject: always va_end even when an error occurs

---
 common.h |  3 +++
 pack.c   | 10 ++++++----
 unpack.c | 13 ++++++++-----
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/common.h b/common.h
index f22f588..abef5af 100644
--- a/common.h
+++ b/common.h
@@ -12,6 +12,9 @@
 
 #define BITMASK(n) (UINTMAX_MAX >> (sizeof (uintmax_t) * CHAR_BIT - n))
 
+#define SET_AND_GOTO(what, to, where) \
+	do { (what) = (to); goto where; } while (0);
+
 #ifndef PRIuSIZE
    #ifdef _WIN32
       #ifdef _WIN64
diff --git a/pack.c b/pack.c
index 002d1ee..4a8228a 100644
--- a/pack.c
+++ b/pack.c
@@ -22,6 +22,7 @@ enum pack_status pack(void *buf_, size_t size, const char *fmt, ...)
 {
 	enum pack_endian endianness = PACK_ENDIAN_BIG;
 	unsigned char *buf = buf_;
+	enum pack_status ret = PACK_OK;
 	size_t offset = 0;
 	va_list ap;
 
@@ -45,15 +46,15 @@ enum pack_status pack(void *buf_, size_t size, const char *fmt, ...)
 		ITYPE_MACROS
 		#undef T
 		case PACK_TYPE_PADDING: v.unsigned_ = 0; sign = false; break;
-		default: return PACK_FMTINVAL;
+		default: SET_AND_GOTO(ret, PACK_FMTINVAL, stop);
 		}
 		tr_debug("i: %d, fmt[i]: %c, sign: %ssigned", i, fmt[i], sign ? "" : "un");
 
 		s = getsize(fmt[i]);
 		tr_debug("s: %" PRIuSIZE, s);
-		if (s == (size_t)-1) return PACK_FMTINVAL;
+		if (s == (size_t)-1) SET_AND_GOTO(ret, PACK_FMTINVAL, stop);
 
-		if (size - offset < s) return PACK_TOOSMALL;
+		if (size - offset < s) SET_AND_GOTO(ret, PACK_TOOSMALL, stop);
 
 		if (sign) {
 			intmax_t n = v.signed_;
@@ -71,7 +72,8 @@ enum pack_status pack(void *buf_, size_t size, const char *fmt, ...)
 		offset += s;
 	}
 
+stop:
 	va_end(ap);
 
-	return PACK_OK;
+	return ret;
 }
diff --git a/unpack.c b/unpack.c
index 472cc8c..3143931 100644
--- a/unpack.c
+++ b/unpack.c
@@ -40,6 +40,7 @@ enum pack_status unpack(const void *buf_, size_t size, const char *fmt, ...)
 {
 	enum pack_endian endianness = PACK_ENDIAN_BIG;
 	const unsigned char *buf = buf_;
+	enum pack_status ret = PACK_OK;
 	size_t offset = 0;
 	va_list ap;
 
@@ -73,7 +74,7 @@ enum pack_status unpack(const void *buf_, size_t size, const char *fmt, ...)
 			errno = 0;
 			c = strtoull(&fmt[i], &end, 10);
 			if ((c == ULLONG_MAX && errno == ERANGE) || c > SIZE_MAX)
-				return PACK_FMTINVAL;
+				SET_AND_GOTO(ret, PACK_FMTINVAL, stop);
 			count = c;
 			i += end - &fmt[i];
 		} else if (fmt[i] == '*') {
@@ -95,15 +96,16 @@ enum pack_status unpack(const void *buf_, size_t size, const char *fmt, ...)
 		case PACK_TYPE_FLOAT: arg.f = va_arg(ap, float *); break;
 		case PACK_TYPE_DOUBLE: arg.d = va_arg(ap, double *); break;
 		case PACK_TYPE_PADDING: break;
-		default: return PACK_FMTINVAL;
+		default: SET_AND_GOTO(ret, PACK_FMTINVAL, stop);
 		}
 		t = fmt[i];
 
 		s = getsize(t);
 		tr_debug("s: %" PRIuSIZE, s);
-		if (s == (size_t)-1) return PACK_FMTINVAL;
+		if (s == (size_t)-1) SET_AND_GOTO(ret, PACK_FMTINVAL, stop);
 
-		if (size - offset < s * count) return PACK_TOOSMALL;
+		if (size - offset < s * count)
+			SET_AND_GOTO(ret, PACK_TOOSMALL, stop);
 
 		if (t == PACK_TYPE_PADDING) goto skip;
 
@@ -149,7 +151,8 @@ skip:
 		offset += s * count;
 	}
 
+stop:
 	va_end(ap);
 
-	return PACK_OK;
+	return ret;
 }
-- 
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