Index: lib/Lex/PPCaching.cpp
===================================================================
--- lib/Lex/PPCaching.cpp
+++ lib/Lex/PPCaching.cpp
@@ -105,8 +105,10 @@
 }
 
 void Preprocessor::EnterCachingLexMode() {
-  if (InCachingLexMode())
+  if (InCachingLexMode()) {
+    assert(CurLexerKind == CLK_CachingLexer && "Unexpected lexer kind");
     return;
+  }
 
   PushIncludeMacroStack();
   CurLexerKind = CLK_CachingLexer;
Index: lib/Lex/PPLexerChange.cpp
===================================================================
--- lib/Lex/PPLexerChange.cpp
+++ lib/Lex/PPLexerChange.cpp
@@ -444,6 +444,7 @@
       }
 
       CurPPLexer = nullptr;
+      recomputeCurLexerKind();
       return true;
     }
 
Index: test/CodeCompletion/Inputs/comments.h
===================================================================
--- test/CodeCompletion/Inputs/comments.h
+++ test/CodeCompletion/Inputs/comments.h
@@ -0,0 +1,4 @@
+// PR32732
+struct B {
+  // <- code completion
+};
Index: test/CodeCompletion/comments.cpp
===================================================================
--- test/CodeCompletion/comments.cpp
+++ test/CodeCompletion/comments.cpp
@@ -0,0 +1,13 @@
+// Note: the run lines follow their respective tests, since line/column
+// matter in this test.
+
+#include "comments.h"
+
+struct A {
+  // <- code completion
+  /* <- code completion */
+};
+
+// RUN: %clang_cc1 -I %S/Inputs -fsyntax-only -code-completion-at=%s:7:6 %s
+// RUN: %clang_cc1 -I %S/Inputs -fsyntax-only -code-completion-at=%s:8:6 %s
+// RUN: %clang_cc1 -I %S/Inputs -fsyntax-only -code-completion-at=%S/Inputs/comments.h:3:6 %s