Update at_path(toml::path) to handle missing component (#168)

* test(paths): check at_path handles missing path component

* fix(paths): update at_path to handle missing component

README.md

@@ -259,6 +259,7 @@ UTF-8 decoding is performed using a state machine based on Bjoern Hoehrmann's '[
 - **[@bobfang1992](https://github.com/bobfang1992)** - Reported a bug and created a [wrapper in python](https://github.com/bobfang1992/pytomlpp)
 - **[@GiulioRomualdi](https://github.com/GiulioRomualdi)** - Added cmake+meson support
 - **[@jonestristand](https://github.com/jonestristand)** - Designed and implemented the `toml::path`s feature
+- **[@kcsaul](https://github.com/kcsaul)** - Fixed a bug
 - **[@levicki](https://github.com/levicki)** - Helped design some new features
 - **[@moorereason](https://github.com/moorereason)** - Reported a whole bunch of bugs
 - **[@mosra](https://github.com/mosra)** - Created the awesome [m.css] used to generate the API docs

include/toml++/impl/path.inl

@@ -504,6 +504,9 @@ TOML_NAMESPACE_START
 				// Error: invalid component
 				return {};
 			}
+
+			if (!current)
+				return {}; // not found
 		}
 
 		return node_view{ current };

tests/path.cpp

@@ -510,6 +510,8 @@ TEST_CASE("path - accessing")
 
 		CHECK(tbl["d"][""]);
 		CHECK(tbl["d"][""] == at_path(tbl, toml::path("d.")));
+
+		CHECK(!at_path(tbl, toml::path("has.missing.component")));
 	}
 
 	SECTION("array")
@@ -535,6 +537,8 @@ TEST_CASE("path - accessing")
 		CHECK(tbl["b"][2]["c"]);
 		CHECK(tbl["b"][2]["c"] == arr.at_path(toml::path("[2].c")));
 		CHECK(tbl["b"][2]["c"] == arr.at_path(toml::path("[2]   \t.c"))); // whitespace is allowed after array indexers
+
+		CHECK(!arr.at_path(toml::path("[3].missing.component")));
 	}
 
 	SECTION("indexing operator")
@@ -580,5 +584,7 @@ TEST_CASE("path - accessing")
 
 		CHECK(tbl["d"][""]);
 		CHECK(tbl["d"][""] == tbl[toml::path("d.")]);
+
+		CHECK(!tbl[toml::path("has.missing.component")]);
 	}
 }

toml.hpp

@@ -11161,6 +11161,9 @@ TOML_NAMESPACE_START
 				// Error: invalid component
 				return {};
 			}
+
+			if (!current)
+				return {}; // not found
 		}
 
 		return node_view{ current };