Replace strlen with strnlen in native code (#5510)

* fix expected vs actual for easier troubleshooting
* replace strlen calls with strnlen

src/libpsl-native/src/followsymlink.cpp

@@ -39,7 +39,7 @@ char* FollowSymLink(const char* fileName)
 
     if (realPath)
     {
-        return strndup(realPath, strlen(realPath) + 1);
+        return strndup(realPath, strnlen(realPath, PATH_MAX));
     }
 
     // if the path wasn't resolved, use readlink

src/libpsl-native/src/getfullyqualifiedname.cpp

@@ -43,7 +43,7 @@ char *GetFullyQualifiedName()
     }
 
     // return the first canonical name in the list
-    fullName = strndup(info->ai_canonname, strlen(info->ai_canonname));
+    fullName = strndup(info->ai_canonname, strnlen(info->ai_canonname, NI_MAXHOST));
 
     // only free info if getaddrinfo was successful
     freeaddrinfo(info);

src/libpsl-native/test/test-createsymlink.cpp

@@ -92,7 +92,7 @@ TEST_F(CreateSymLinkTest, SymLinkToFile)
     std::string target = FollowSymLink(fileSymLink.c_str());
     char buffer[PATH_MAX];
     std::string expected = realpath(file, buffer);
-    EXPECT_EQ(target, expected);
+    EXPECT_EQ(expected, target);
 }
 
 TEST_F(CreateSymLinkTest, SymLinkToDirectory)
@@ -103,7 +103,7 @@ TEST_F(CreateSymLinkTest, SymLinkToDirectory)
     std::string target = FollowSymLink(dirSymLink.c_str());
     char buffer[PATH_MAX];
     std::string expected = realpath(dir, buffer);
-    EXPECT_EQ(target, expected);
+    EXPECT_EQ(expected, target);
 }
 
 TEST_F(CreateSymLinkTest, SymLinkAgain)