Fixed error when normalizing paths with adjacent slashes (i.e. empty segments) (#123)

* Fixed error when normalizing paths with adjacent slashes (i.e. empty segments)

* Attempt to fix test failures occuring on Visual Studio

* Updated implementation of path normalization based on review suggestion

Author: glynos

src/detail/uri_normalize.cpp

@@ -30,15 +30,14 @@ std::string normalize_path_segments(string_view path) {
       return ch == '/';
     });
 
-    // remove single dot segments
-    detail::remove_erase_if(
-        path_segments, [](const std::string& s) { return (s == "."); });
-
-    // remove double dot segments
+    bool last_segment_is_slash = path_segments.back().empty();
     std::vector<std::string> normalized_segments;
-    for (auto& segment : path_segments) {
-      if (segment == "..") {
-        if (normalized_segments.size() <= 1) {
+    for (const auto &segment : path_segments) {
+      if (segment.empty() || (segment == ".")) {
+        continue;
+      }
+      else if (segment == "..") {
+        if (normalized_segments.empty()) {
           throw uri_builder_error();
         }
         normalized_segments.pop_back();
@@ -48,19 +47,13 @@ std::string normalize_path_segments(string_view path) {
       }
     }
 
-    // remove adjacent slashes
-    optional<std::string> prev_segment;
-    detail::remove_erase_if(
-        normalized_segments, [&prev_segment](const std::string& segment) {
-          bool has_adjacent_slash =
-              ((prev_segment && prev_segment->empty()) && segment.empty());
-          if (!has_adjacent_slash) {
-            prev_segment = segment;
-          }
-          return has_adjacent_slash;
-        });
-
-    result = network_boost::join(normalized_segments, "/");
+    for (const auto &segment : normalized_segments) {
+      result += "/" + segment;
+    }
+    
+    if (last_segment_is_slash) {
+      result += "/";
+    }
   }
 
   if (result.empty()) {

test/uri_normalization_test.cpp

@@ -196,3 +196,17 @@ TEST(uri_normalization_test, query_percent_encoded_unreserved) {
   ASSERT_EQ("http://www.example.com/?foo=alpha123-._~",
             instance.normalize(network::uri_comparison_level::syntax_based).string());
 }
+
+TEST(uri_test, path_adjacent_slashes_122) {
+  // https://github.com/cpp-netlib/uri/issues/122
+  network::uri instance("http://www.example.com/abc//elementary");
+  ASSERT_EQ("http://www.example.com/abc/elementary",
+            instance.normalize(network::uri_comparison_level::syntax_based).string());
+}
+
+TEST(uri_test, path_adjacent_slashes_122_part_2) {
+  // https://github.com/cpp-netlib/uri/issues/122
+  network::uri instance("http://www.example.com/abc//.//../elementary");
+  ASSERT_EQ("http://www.example.com/elementary",
+            instance.normalize(network::uri_comparison_level::syntax_based).string());
+}

test/uri_test.cpp

@@ -1068,4 +1068,4 @@ TEST(uri_test, assignment_operator_bug_116) {
 
   a = b;
   ASSERT_FALSE(a.has_port()) << a.string() << ", " << a.port();
-}
+}