[fm2js] Fail transpiling if lexer has left over data

If there is remaining data after the lexer has said it's complete then
something has gone wrong while lexing the formcalc data. This CL changes
the transpiler to return an error in the case of the lexer havign extra
data.

Bug: chromium:834575
Change-Id: I8a1288a7f01cc69faf2033829d68246d815258de
Reviewed-on: https://pdfium-review.googlesource.com/32130
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/xfa/fxfa/fm2js/cxfa_fmlexer_unittest.cpp b/xfa/fxfa/fm2js/cxfa_fmlexer_unittest.cpp
index 248b9fead6..cefc1cb992 100644
--- a/xfa/fxfa/fm2js/cxfa_fmlexer_unittest.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmlexer_unittest.cpp
@@ -15,12 +15,14 @@ TEST(CXFA_FMLexerTest, NullString) {
   CXFA_FMLexer lexer(null_string);
   CXFA_FMToken token = lexer.NextToken();
   EXPECT_EQ(TOKeof, token.m_type);
+  EXPECT_TRUE(lexer.IsComplete());
 }
 
 TEST(CXFA_FMLexerTest, EmptyString) {
   CXFA_FMLexer lexer(L"");
   CXFA_FMToken token = lexer.NextToken();
   EXPECT_EQ(TOKeof, token.m_type);
+  EXPECT_TRUE(lexer.IsComplete());
 }
 
 TEST(CXFA_FMLexerTest, Numbers) {
@@ -67,6 +69,7 @@ TEST(CXFA_FMLexerTest, Numbers) {
   // prior to the exponent.
   // EXPECT_EQ(L"100000000000000000", token.m_string);
   EXPECT_EQ(L"99999999999999999", token.m_string);
+  EXPECT_TRUE(lexer->IsComplete());
 }
 
 // The quotes are stripped in CXFA_FMStringExpression::ToJavaScript.
@@ -99,6 +102,7 @@ TEST(CXFA_FMLexerTest, Strings) {
   EXPECT_EQ(
       L"\"\\u0047\\u006f\\u0066\\u0069\\u0073\\u0068\\u0021\\u000d\\u000a\"",
       token.m_string);
+  EXPECT_TRUE(lexer->IsComplete());
 }
 
 // Note, 'this' is a keyword but is not matched by the lexer.
@@ -170,6 +174,7 @@ TEST(CXFA_FMLexerTest, OperatorsAndKeywords) {
     auto lexer = pdfium::MakeUnique<CXFA_FMLexer>(op[i].op);
     CXFA_FMToken token = lexer->NextToken();
     EXPECT_EQ(op[i].token, token.m_type);
+    EXPECT_TRUE(lexer->IsComplete());
   }
 }
 
@@ -213,6 +218,7 @@ TEST(CXFA_FMLexerTest, Comments) {
 
   token = lexer->NextToken();
   EXPECT_EQ(TOKeof, token.m_type);
+  EXPECT_TRUE(lexer->IsComplete());
 }
 
 TEST(CXFA_FMLexerTest, ValidIdentifiers) {
@@ -223,6 +229,7 @@ TEST(CXFA_FMLexerTest, ValidIdentifiers) {
     CXFA_FMToken token = lexer->NextToken();
     EXPECT_EQ(TOKidentifier, token.m_type);
     EXPECT_EQ(ident, token.m_string);
+    EXPECT_TRUE(lexer->IsComplete());
   }
 }
 
@@ -248,6 +255,7 @@ TEST(CXFA_FMLexerTest, InvalidIdentifiers) {
   EXPECT_NE(TOKreserver, token.m_type);
   token = lexer->NextToken();
   EXPECT_EQ(TOKreserver, token.m_type);
+  EXPECT_FALSE(lexer->IsComplete());
 }
 
 TEST(CXFA_FMLexerTest, Whitespace) {
@@ -266,4 +274,20 @@ TEST(CXFA_FMLexerTest, Whitespace) {
 
   token = lexer->NextToken();
   EXPECT_EQ(TOKeof, token.m_type);
+  EXPECT_TRUE(lexer->IsComplete());
+}
+
+TEST(CXFA_FMLexerTest, NullData) {
+  auto lexer = pdfium::MakeUnique<CXFA_FMLexer>(
+      WideStringView(L"\x2d\x32\x00\x2d\x32", 5));
+  CXFA_FMToken token = lexer->NextToken();
+  EXPECT_EQ(TOKminus, token.m_type);
+
+  token = lexer->NextToken();
+  EXPECT_EQ(TOKnumber, token.m_type);
+  EXPECT_EQ(L"2", token.m_string);
+
+  token = lexer->NextToken();
+  EXPECT_EQ(TOKeof, token.m_type);
+  EXPECT_FALSE(lexer->IsComplete());
 }