Speculative fix for null deref above ThrowNoDefaultPropertyException

Avoid possibility of an unterminated string or nullptr by avoiding
stringviews, since the non-view classes copy and always provide
a suitable result. Always use %ls and widestrings in wprintf()
variants, since that combination is consistent across our platforms
(%s, %S, etc. have idiosyncracies).

Bug: 870952
Change-Id: Ief62a42c3486e8298f9583b56e9333db1a74972a
Reviewed-on: https://pdfium-review.googlesource.com/39551
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 5 insertions, 6 deletions

diff --git a/fxjs/cfxjse_formcalc_context.cpp b/fxjs/cfxjse_formcalc_context.cpp
index cf42fb26c7..4201059c06 100644
--- a/fxjs/cfxjse_formcalc_context.cpp
+++ b/fxjs/cfxjse_formcalc_context.cpp
@@ -6199,9 +6199,8 @@ void CFXJSE_FormCalcContext::GlobalPropertyGetter(CFXJSE_Value* pValue) {
 
 void CFXJSE_FormCalcContext::ThrowNoDefaultPropertyException(
     const ByteStringView& name) const {
-  // TODO(tsepez): check usage of c_str() below.
-  ThrowException(L"%.16S doesn't have a default property.",
-                 name.unterminated_c_str());
+  ThrowException(L"%ls doesn't have a default property.",
+                 WideString::FromUTF8(name).c_str());
 }
 
 void CFXJSE_FormCalcContext::ThrowCompilerErrorException() const {
@@ -6220,14 +6219,14 @@ void CFXJSE_FormCalcContext::ThrowPropertyNotInObjectException(
     const WideString& name,
     const WideString& exp) const {
   ThrowException(
-      L"An attempt was made to reference property '%.16s' of a non-object "
-      L"in SOM expression %.16s.",
+      L"An attempt was made to reference property '%ls' of a non-object "
+      L"in SOM expression %ls.",
       name.c_str(), exp.c_str());
 }
 
 void CFXJSE_FormCalcContext::ThrowParamCountMismatchException(
     const WideString& method) const {
-  ThrowException(L"Incorrect number of parameters calling method '%.16s'.",
+  ThrowException(L"Incorrect number of parameters calling method '%ls'.",
                  method.c_str());
 }