3 files changed, 15 insertions, 2 deletions
diff --git a/clang/test/Misc/serialized-diags-no-category.c b/clang/test/Misc/serialized-diags-no-category.c
new file mode 100644
index 00000000000..9c92ac33309
--- /dev/null
+++ b/clang/test/Misc/serialized-diags-no-category.c
@@ -0,0 +1,12 @@
+#error foo
+#error bar
+
+// RUN: rm -f %t
+// RUN: %clang -ferror-limit=1 -fsyntax-only %s --serialize-diagnostics %t > /dev/null 2>&1 || true
+// RUN: c-index-test -read-diagnostics %t 2>&1 | FileCheck %s
+
+// This test case tests that we can handle both fatal errors and errors without categories.
+
+// CHECK: {{.*[/\\]}}serialized-diags-no-category.c:1:2: error: #error foo []
+// CHECK: Number of diagnostics: 2
+
diff --git a/clang/test/Misc/serialized-diags.c b/clang/test/Misc/serialized-diags.c
index 7cdac53b84d..b5b619d655b 100644
--- a/clang/test/Misc/serialized-diags.c
+++ b/clang/test/Misc/serialized-diags.c
@@ -16,7 +16,7 @@ void qux(int x) {
 }
 
 // RUN: rm -f %t
-// RUN: %clang -Wall -fsyntax-only %s --serialize-diagnostics %t 2>&1 /dev/null || true
+// RUN: %clang -Wall -fsyntax-only %s --serialize-diagnostics %t > /dev/null 2>&1 || true
 // RUN: c-index-test -read-diagnostics %t 2>&1 | FileCheck %s
 
 // This test case tests that we can handle multiple diagnostics which contain
diff --git a/clang/tools/libclang/CXLoadedDiagnostic.cpp b/clang/tools/libclang/CXLoadedDiagnostic.cpp
index 61b9e33c2da..b95515e6e22 100644
--- a/clang/tools/libclang/CXLoadedDiagnostic.cpp
+++ b/clang/tools/libclang/CXLoadedDiagnostic.cpp
@@ -595,7 +595,8 @@ LoadResult DiagLoader::readDiagnosticBlock(llvm::BitstreamCursor &Stream,
         continue;
       case serialized_diags::RECORD_CATEGORY:
         if (readString(TopDiags, TopDiags.Categories, "category", Record,
-                       BlobStart, BlobLen))
+                       BlobStart, BlobLen,
+                       /* allowEmptyString */ true))
           return Failure;
         continue;