Compare document path.

src/compare/diff.rs

@@ -438,9 +438,31 @@ pub fn compare_document<'s>(
         Ok(_) => {}
     }
 
-    // TODO: Compare :path
+    // Compare :path
     // :path is a quoted string to the absolute path of the document.
     let document_path = get_property_quoted_string(emacs, ":path")?;
+    let rust_document_path = rust.path.as_ref().map(|p| p.to_str()).flatten();
+    match (
+        document_path.as_ref().map(|s| s.as_str()),
+        rust_document_path,
+    ) {
+        (None, None) => {}
+        (None, Some(_)) | (Some(_), None) => {
+            this_status = DiffStatus::Bad;
+            message = Some(format!(
+                "Path mismatch (emacs != rust) {:?} != {:?}",
+                document_path, rust_document_path
+            ));
+        }
+        (Some(e), Some(r)) if e != r => {
+            this_status = DiffStatus::Bad;
+            message = Some(format!(
+                "Path mismatch (emacs != rust) {:?} != {:?}",
+                document_path, rust_document_path
+            ));
+        }
+        (Some(_), Some(_)) => {}
+    };
 
     // Compare category
     // :CATEGORY is specified either from "#+CATEGORY:" or it is the file name without the ".org" extension.