commit bbea4d5e6b82a683dccaa8f4916e2a44f5dd3490
Author: Sylvestre Ledru <sylvestre@debian.org>
Date:   Wed Jul 8 13:33:34 2020 +0200

    clang: Don't show a trailing space with --version when not built from the repo
    
    Reported here:
    https://bugs.llvm.org/show_bug.cgi?id=38998#c15
    
    Reviewers: hans
    
    Differential Revision: https://reviews.llvm.org/D83386

diff --git a/clang/lib/Basic/Version.cpp b/clang/lib/Basic/Version.cpp
index c4b7d34ed16..286107cab9d 100644
--- a/clang/lib/Basic/Version.cpp
+++ b/clang/lib/Basic/Version.cpp
@@ -97,8 +97,12 @@ std::string getClangToolFullVersion(StringRef ToolName) {
 #ifdef CLANG_VENDOR
   OS << CLANG_VENDOR;
 #endif
-  OS << ToolName << " version " CLANG_VERSION_STRING " "
-     << getClangFullRepositoryVersion();
+  OS << ToolName << " version " CLANG_VERSION_STRING;
+
+  std::string repo = getClangFullRepositoryVersion();
+  if (!repo.empty()) {
+    OS << " " << repo;
+  }
 
   return OS.str();
 }
@@ -111,7 +115,13 @@ std::string getClangFullCPPVersion() {
 #ifdef CLANG_VENDOR
   OS << CLANG_VENDOR;
 #endif
-  OS << "Clang " CLANG_VERSION_STRING " " << getClangFullRepositoryVersion();
+  OS << "Clang " CLANG_VERSION_STRING;
+
+  std::string repo = getClangFullRepositoryVersion();
+  if (!repo.empty()) {
+    OS << " " << repo;
+  }
+
   return OS.str();
 }