Fixed multiaddress_get_peer_id to return allocated memory

Returing in place causes problems with continuations i.e. ending
slashes. Therefore it is better to return allocated memory.

include/multiaddr/base58.h

@@ -1,11 +1,3 @@
-//
-//  base58.h
-//  libp2p_xcode
-//
-//  Created by John Jones on 11/7/16.
-//  Copyright © 2016 JMJAtlanta. All rights reserved.
-//
-
 #ifndef base58_h
 #define base58_h
 #include "varint.h"

include/multiaddr/multiaddr.h

@@ -83,7 +83,7 @@ int multiaddress_get_ip_port(const struct MultiAddress* in);
 /**
  * Pulls the peer ID out of a multiaddress struct
  * @param in the MultiAddress
- * @returns a pointer to the peer id string, or NULL
+ * @returns the peer id string, or NULL NOTE: This allocates memory that needs to be freed
  */
 char* multiaddress_get_peer_id(const struct MultiAddress* in);
 

multiaddr.c

@@ -159,10 +159,28 @@ int multiaddress_get_ip_port(const struct MultiAddress* in) {
 }
 
 char* multiaddress_get_peer_id(const struct MultiAddress* in) {
-	char* ptr = strstr(in->string, "/ipfs/");
-	if (ptr == NULL)
-		return NULL;
-	return &ptr[6];
+	char* result = NULL;
+	int str_len = 0;
+	char* slash = NULL;
+	char* ptr = NULL;
+
+	ptr = strstr(in->string, "/ipfs/");
+	if (ptr != NULL && ptr[6] != 0) {
+		ptr += 6;
+		str_len = strlen(ptr);
+		slash = strchr(ptr, '/');
+		if (slash != NULL) {
+			str_len = slash - ptr;
+		}
+		if (str_len > 0) {
+			result = malloc(str_len + 1);
+			if (result != NULL) {
+				memset(result, 0, str_len);
+				memcpy(result, ptr, str_len);
+			}
+		}
+	}
+	return result;
 }
 
 void multiaddress_free(struct MultiAddress* in) {

test_multiaddr.h

@@ -114,7 +114,7 @@ int test_multiaddr_peer_id() {
 	char full_string[255];
 	char* result = NULL;
 	char* bytes = NULL;
-	int retVal = 0;
+	int retVal = 0, port = 0;
 	struct MultiAddress *addr = NULL, *addr2 = NULL;
 
 	sprintf(full_string, "/ip4/127.0.0.1/tcp/4001/ipfs/%s/", orig_address);
@@ -123,9 +123,10 @@ int test_multiaddr_peer_id() {
 
 	result = multiaddress_get_peer_id(addr);
 
-	if (result == NULL || strncmp(result, orig_address, strlen(orig_address)) != 0)
+	if (result == NULL || strcmp(result, orig_address) != 0)
 		goto exit;
 
+	free(result);
 	result = NULL;
 
 	// switch to bytes and back again to verify the peer id follows...
@@ -155,12 +156,20 @@ int test_multiaddr_peer_id() {
 		goto exit;
 	}
 
-	int port = multiaddress_get_ip_port(addr2);
+	port = multiaddress_get_ip_port(addr2);
 	if (port != 4001) {
 		fprintf(stderr, "Original string had port 4001, but now reporting %d\n", port);
 		goto exit;
 	}
 
+	result = multiaddress_get_peer_id(addr2);
+	if (strcmp(result, orig_address) != 0) {
+		fprintf(stderr, "New peer id %s does not match %s", result, orig_address);
+		goto exit;
+	}
+	free(result);
+	result = NULL;
+
 	retVal = 1;
 	exit:
 	if (addr != NULL)
@@ -174,6 +183,30 @@ int test_multiaddr_peer_id() {
 	return retVal;
 }
 
+int test_multiaddr_get_peer_id() {
+	char* orig_address = "QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG";
+	char full_string[255];
+	char* result = NULL;
+	int retVal = 0;
+	struct MultiAddress *addr = NULL;
+
+	sprintf(full_string, "/ip4/127.0.0.1/tcp/4001/ipfs/%s/", orig_address);
+
+	addr = multiaddress_new_from_string(full_string);
+
+	result = multiaddress_get_peer_id(addr);
+
+	if (result == NULL || strcmp(result, orig_address) != 0)
+		goto exit;
+
+	retVal = 1;
+	exit:
+	multiaddress_free(addr);
+	free(result);
+	result = NULL;
+	return retVal;
+}
+
 int test_multiaddr_bytes() {
 	int retVal = 0;
 	char* orig_address = "/ip4/127.0.0.1/tcp/4001/";

testing.c

@@ -9,6 +9,7 @@ const char* names[] = {
 		"test_int_to_hex",
 		"test_multiaddr_utils",
 		"test_multiaddr_peer_id",
+		"test_multiaddr_get_peer_id",
 		"test_multiaddr_bytes"
 };
 
@@ -19,6 +20,7 @@ int (*funcs[])(void) = {
 		test_int_to_hex,
 		test_multiaddr_utils,
 		test_multiaddr_peer_id,
+		test_multiaddr_get_peer_id,
 		test_multiaddr_bytes
 };