Fixed protobuf bugs and added 3rd example of a complex object

protobuf.c

@@ -48,6 +48,7 @@ int protobuf_encode_string(int field_number, enum WireType field_type, const cha
  */
 int protobuf_encode_varint(int field_number, enum WireType field_type, unsigned long long incoming, unsigned char* buffer,
 		size_t max_buffer_length, size_t* bytes_written) {
+	*bytes_written = 0;
 	// push the field number and wire type together
 	unsigned int field_no = field_number << 3;
 	unsigned long long field = field_no | field_type;
@@ -72,17 +73,20 @@ int protobuf_encode_varint(int field_number, enum WireType field_type, unsigned
  */
 int protobuf_decode_string(const unsigned char* buffer, size_t buffer_length, char** results, size_t* bytes_read) {
 	size_t pos = 0;
+	*bytes_read = 0;
 	// grab the field size
 	int length = varint_decode(&buffer[pos], buffer_length - pos, bytes_read);
 	pos += *bytes_read;
 
 	// allocate memory
-	*results = malloc(sizeof(char) * length);
+	*results = malloc(sizeof(char) * length + 1);
 	if ((*results) == NULL)
 		return 0;
 
 	// copy the string
 	memcpy((*results), &buffer[pos], length);
+	// don't forget the null
+	(*results)[length] = 0;
 	pos += length;
 	*bytes_read = pos;
 
@@ -98,9 +102,10 @@ int protobuf_decode_string(const unsigned char* buffer, size_t buffer_length, ch
  * @param bytes_read the number of bytes read from the buffer
  */
 int protobuf_decode_field_and_type(const unsigned char* buffer, int buffer_length, int *field_no, enum WireType *field_type, size_t* bytes_read) {
+	*bytes_read = 0;
 	unsigned long long field = varint_decode(buffer, buffer_length, bytes_read);
 	*field_no = field >> 3;
-	*field_type = field | *field_no;
+	*field_type = field & *field_no;
 	return 1;
 }
 

test/Test1_protobuf.c

@@ -38,6 +38,7 @@ int Test1_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Te
 			Test1_free(*output);
 			return 0;
 		}
+		pos += bytes_read;
 		switch (field_no) {
 			case (1):
 				(*output)->a = varint_decode(&buffer[pos], buffer_length - pos, &bytes_read);

test/Test3_protobuf.c

@@ -33,7 +33,16 @@ int Test3_protobuf_encode(struct Test3* incoming, unsigned char* buffer, size_t
 	*bytes_written += bytes_used;
 	protobuf_encode_varint(2, Test3_message_fields[1], incoming->an_int, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
 	*bytes_written += bytes_used;
-	return Test2_protobuf_encode(incoming->test2, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
+	// write Test2 to safe area
+	int pos = *bytes_written + 11;
+	size_t test2_size = 0;
+	int retVal = Test2_protobuf_encode(incoming->test2, &buffer[pos], max_buffer_length - pos, &test2_size);
+	protobuf_encode_varint(3, Test3_message_fields[2], test2_size, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
+	*bytes_written += bytes_used;
+	// now move the encoded Test2 to the correct area
+	memcpy(&buffer[*bytes_written], &buffer[pos], test2_size);
+	*bytes_written += test2_size;
+	return retVal;
 }
 
 int Test3_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Test3** output) {
@@ -59,10 +68,13 @@ int Test3_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct Te
 				(*output)->an_int = varint_decode(&buffer[pos], buffer_length - pos, &bytes_read);
 				pos += bytes_read;
 				break;
-			case(3):
-				Test2_protobuf_decode(&buffer[pos], buffer_length - pos, &((*output)->test2));
+			case(3): {
+				size_t test2_size = varint_decode(&buffer[pos], buffer_length - pos, &bytes_read);
 				pos += bytes_read;
+				Test2_protobuf_decode(&buffer[pos], buffer_length - pos, &((*output)->test2));
+				pos += test2_size;
 				break;
+			}
 		}
 	}
 	return 1;

test/test_protobuf.h

@@ -65,7 +65,7 @@ int test_complex_protobuf() {
 		return 0;
 	}
 
-	if (strcmp(results->test2->a, test3->test2->a) == 0) {
+	if (strcmp(results->test2->a, test3->test2->a) != 0) {
 		printf("String a does not match: %s vs %s\n", test3->test2->a, results->test2->a);
 		Test3_free(test3);
 		Test3_free(results);
@@ -145,6 +145,15 @@ int test_write_simple() {
 		return 0;
 	}
 
+	struct Test1* results;
+	retVal = Test1_protobuf_decode(buffer, bytes_written, &results);
+
+	if (results->a != test1.a) {
+		printf("Incorrect results after decode");
+		Test1_free(results);
+		return 0;
+	}
+
 	return 1;
 }
 

varint.c

@@ -61,6 +61,7 @@ unsigned char* varint_encode(const unsigned long long n, unsigned char* buf, int
  */
 unsigned long long varint_decode(const unsigned char* buf, int len, size_t* bytes) {
   unsigned long long result = 0;
+  if (bytes != NULL) *bytes = 0;
   int bits = 0;
   const unsigned char* ptr = buf;
   unsigned long long ll;