3 files changed, 7 insertions, 14 deletions
diff --git a/xfa/fde/css/cfde_cssselector.cpp b/xfa/fde/css/cfde_cssselector.cpp
index 6842d58738..c1e9f7f22a 100644
--- a/xfa/fde/css/cfde_cssselector.cpp
+++ b/xfa/fde/css/cfde_cssselector.cpp
@@ -8,24 +8,18 @@
 
 #include <utility>
 
+#include "core/fxcrt/fx_extension.h"
 #include "third_party/base/ptr_util.h"
 
 namespace {
 
-bool IsCSSChar(wchar_t wch) {
-  return (wch >= 'a' && wch <= 'z') || (wch >= 'A' && wch <= 'Z');
-}
-
 int32_t GetCSSNameLen(const wchar_t* psz, const wchar_t* pEnd) {
   const wchar_t* pStart = psz;
   while (psz < pEnd) {
     wchar_t wch = *psz;
-    if (IsCSSChar(wch) || (wch >= '0' && wch <= '9') || wch == '_' ||
-        wch == '-') {
-      ++psz;
-    } else {
+    if (!FXSYS_iswalnum(wch) && wch != '_' && wch != '-')
       break;
-    }
+    ++psz;
   }
   return psz - pStart;
 }
@@ -73,7 +67,7 @@ std::unique_ptr<CFDE_CSSSelector> CFDE_CSSSelector::FromString(
   std::unique_ptr<CFDE_CSSSelector> pFirst = nullptr;
   for (psz = pStart; psz < pEnd;) {
     wchar_t wch = *psz;
-    if (IsCSSChar(wch) || wch == '*') {
+    if (FXSYS_iswalpha(wch) || wch == '*') {
       int32_t iNameLen = wch == '*' ? 1 : GetCSSNameLen(psz, pEnd);
       auto p = pdfium::MakeUnique<CFDE_CSSSelector>(
           FDE_CSSSelectorType::Element, psz, iNameLen, true);
diff --git a/xfa/fde/css/cfde_csssyntaxparser.cpp b/xfa/fde/css/cfde_csssyntaxparser.cpp
index ac1abcc665..bc861bdd6e 100644
--- a/xfa/fde/css/cfde_csssyntaxparser.cpp
+++ b/xfa/fde/css/cfde_csssyntaxparser.cpp
@@ -9,14 +9,14 @@
 #include <algorithm>
 
 #include "core/fxcrt/fx_codepage.h"
+#include "core/fxcrt/fx_extension.h"
 #include "xfa/fde/css/cfde_cssdeclaration.h"
 #include "xfa/fde/css/fde_cssdatatable.h"
 
 namespace {
 
 bool IsSelectorStart(wchar_t wch) {
-  return wch == '.' || wch == '#' || wch == '*' || (wch >= 'a' && wch <= 'z') ||
-         (wch >= 'A' && wch <= 'Z');
+  return wch == '.' || wch == '#' || wch == '*' || FXSYS_iswalpha(wch);
 }
 
 }  // namespace
diff --git a/xfa/fde/css/cfde_cssvaluelistparser.cpp b/xfa/fde/css/cfde_cssvaluelistparser.cpp
index 36d5edc3c7..84dc20b328 100644
--- a/xfa/fde/css/cfde_cssvaluelistparser.cpp
+++ b/xfa/fde/css/cfde_cssvaluelistparser.cpp
@@ -30,8 +30,7 @@ bool CFDE_CSSValueListParser::NextValue(FDE_CSSPrimitiveType& eType,
     iLength = SkipTo(' ', false, false);
     if (iLength == 4 || iLength == 7)
       eType = FDE_CSSPrimitiveType::RGB;
-  } else if ((wch >= '0' && wch <= '9') || wch == '.' || wch == '-' ||
-             wch == '+') {
+  } else if (std::iswdigit(wch) || wch == '.' || wch == '-' || wch == '+') {
     while (m_pCur < m_pEnd && (*m_pCur > ' ' && *m_pCur != m_Separator))
       ++m_pCur;