Rewrote escape_some_html() slightly and enhanced the test.

src/gitea2rss.hpp

@@ -62,6 +62,6 @@ const string get_repo(const string &url);
 const string get_project(const string &url);
 
 //! Escape some characters to named HTML entities.
-const string escape_some_html(const string &html);
+const string escape_some_html(string html);
 
 #endif  // GITEA2RSS_HPP

src/strings.cpp

@@ -42,19 +42,19 @@ const string get_project(const string &url)
     return repo.substr(repo.find('/') + 1);
 }
 
-const string escape_some_html(const string &html)
+const string escape_some_html(string html)
 {
-    string output = html;
-    const std::map<char, string> names =
+    const std::map<const char, const string> names =
         {
             { '<', "&lt;" },
             { '>', "&gt;" }
         };
+
     for (auto &pair : names)
     {
         const std::regex re(string(1, pair.first));
-        output = std::regex_replace(output, re, pair.second);
+        html = std::regex_replace(html, re, pair.second);
     }
 
-    return output;
+    return html;
 }

tests/test_escape_some_html.cpp

@@ -25,11 +25,12 @@ SCENARIO ("escape_some_html() works as expected", "[strings]")
     WHEN ("String with escape-able characters")
     {
         const string escaped
-            = escape_some_html("<Anna & Arthur are escaping HTML.>");
+            = escape_some_html("<p><small>.</small></p>");
 
         THEN ("The HTML is escaped")
         {
-            REQUIRE(escaped == "&lt;Anna & Arthur are escaping HTML.&gt;");
+            REQUIRE(escaped ==
+                    "&lt;p&gt;&lt;small&gt;.&lt;/small&gt;&lt;/p&gt;");
         }
     }
 }