DataExtractor: Fix integer truncation issues in LEB128 extraction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162201 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/unittests/Support/DataExtractorTest.cpp b/unittests/Support/DataExtractorTest.cpp
index 9813e46..ec8bd3d 100644
--- a/unittests/Support/DataExtractorTest.cpp
+++ b/unittests/Support/DataExtractorTest.cpp
@@ -16,6 +16,7 @@
 const char numberData[] = "\x80\x90\xFF\xFF\x80\x00\x00\x00";
 const char stringData[] = "hellohello\0hello";
 const char leb128data[] = "\xA6\x49";
+const char bigleb128data[] = "\xAA\xA9\xFF\xAA\xFF\xAA\xFF\x4A";
 
 TEST(DataExtractorTest, OffsetOverflow) {
   DataExtractor DE(StringRef(numberData, sizeof(numberData)-1), false, 8);
@@ -106,6 +107,14 @@
   offset = 0;
   EXPECT_EQ(-7002LL, DE.getSLEB128(&offset));
   EXPECT_EQ(2U, offset);
+
+  DataExtractor BDE(StringRef(bigleb128data, sizeof(bigleb128data)-1), false,8);
+  offset = 0;
+  EXPECT_EQ(42218325750568106ULL, BDE.getULEB128(&offset));
+  EXPECT_EQ(8U, offset);
+  offset = 0;
+  EXPECT_EQ(-29839268287359830LL, BDE.getSLEB128(&offset));
+  EXPECT_EQ(8U, offset);
 }
 
 }