ignore empty freestanding paragraphs

Author: tcottin

clang-tools-extra/clangd/SymbolDocumentation.h

@@ -127,8 +127,10 @@ class SymbolDocCommentVisitor
                             llvm::raw_string_ostream &Out) const;
 
   void visitParagraphComment(const comments::ParagraphComment *P) {
-    FreeParagraphs[CommentPartIndex] = P;
-    CommentPartIndex++;
+    if (!P->isWhitespace()) {
+      FreeParagraphs[CommentPartIndex] = P;
+      CommentPartIndex++;
+    }
   }
 
   void visitParamCommandComment(const comments::ParamCommandComment *P) {

clang-tools-extra/clangd/unittests/SymbolDocumentationTests.cpp

@@ -292,6 +292,14 @@ Another paragraph)",
 this is not treated as brief
 
 Another paragraph)"},
+      {R"(
+@brief Some brief
+)",
+       "", "", ""},
+      {R"(
+Some brief
+)",
+       "", "", ""},
   };
   for (const auto &C : Cases) {
     markup::Document Doc;