CXFA_FMStringExpression: int16_t is not a good type for a string index.

Use early return while we're at it.

Bug: 716519
Change-Id: I4630d8b6121266c76a53f0171ba6dfd307da725a
Reviewed-on: https://pdfium-review.googlesource.com/4611
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/xfa/fxfa/fm2js/xfa_simpleexpression_unittest.cpp b/xfa/fxfa/fm2js/xfa_simpleexpression_unittest.cpp
index 160c4a12c4..b1b96e03d5 100644
--- a/xfa/fxfa/fm2js/xfa_simpleexpression_unittest.cpp
+++ b/xfa/fxfa/fm2js/xfa_simpleexpression_unittest.cpp
@@ -7,6 +7,7 @@
 #include <memory>
 #include <utility>
 
+#include "core/fxcrt/fx_string.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/test_support.h"
 #include "third_party/base/ptr_util.h"
@@ -41,3 +42,35 @@ TEST(FMCallExpressionTest, more_than_32_arguments) {
 
   EXPECT_EQ(result.AsStringC(), js.AsStringC());
 }
+
+TEST(FMStringExpressionTest, Empty) {
+  CFX_WideTextBuf accumulator;
+  CXFA_FMStringExpression(1, CFX_WideStringC()).ToJavaScript(accumulator);
+  EXPECT_EQ(L"", accumulator.AsStringC());
+}
+
+TEST(FMStringExpressionTest, Short) {
+  CFX_WideTextBuf accumulator;
+  CXFA_FMStringExpression(1, L"a").ToJavaScript(accumulator);
+  EXPECT_EQ(L"a", accumulator.AsStringC());
+}
+
+TEST(FMStringExpressionTest, Medium) {
+  CFX_WideTextBuf accumulator;
+  CXFA_FMStringExpression(1, L".abcd.").ToJavaScript(accumulator);
+  EXPECT_EQ(L"\"abcd\"", accumulator.AsStringC());
+}
+
+TEST(FMStringExpressionTest, Long) {
+  CFX_WideTextBuf accumulator;
+  std::vector<CFX_WideStringC::UnsignedType> vec(140000, L'A');
+  CXFA_FMStringExpression(1, CFX_WideStringC(vec)).ToJavaScript(accumulator);
+  EXPECT_EQ(140000, accumulator.GetLength());
+}
+
+TEST(FMStringExpressionTest, Quoted) {
+  CFX_WideTextBuf accumulator;
+  CXFA_FMStringExpression(1, L".Simon says \"\"run\"\".")
+      .ToJavaScript(accumulator);
+  EXPECT_EQ(L"\"Simon says \\\"run\\\"\"", accumulator.AsStringC());
+}