Fix PCHs that import more than one module

We were passing < to std::unique, but it expects ==. Since the input is
sorted, we were always trimming it to one entry.

llvm-svn: 217402

1 files changed, 4 insertions, 1 deletions

diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 973d8a28e14..0b65d0a571d 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4617,10 +4617,13 @@ void ASTWriter::WriteASTCore(Sema &SemaRef,
       auto Cmp = [](const ModuleInfo &A, const ModuleInfo &B) {
         return A.ID < B.ID;
       };
+      auto Eq = [](const ModuleInfo &A, const ModuleInfo &B) {
+        return A.ID == B.ID;
+      };
 
       // Sort and deduplicate module IDs.
       std::sort(Imports.begin(), Imports.end(), Cmp);
-      Imports.erase(std::unique(Imports.begin(), Imports.end(), Cmp),
+      Imports.erase(std::unique(Imports.begin(), Imports.end(), Eq),
                     Imports.end());
 
       RecordData ImportedModules;