Merge to XFA: Reland "Cleanup some numeric code.""

This reverts commit 0569ab0b11b723d9bca4ddd642b0cf8828c4bdd1.

This changes the various comparisons of char >= '0' && char <= '9' and
char < '0' || char > '9' to use std::isdigit checks. It also cleans up
a handful of hex to digit conversions to call one common method.

R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1449873003 .

(cherry picked from commit 3f148915d12f54a946a0c0bf526162b79c39d650)

Review URL: https://codereview.chromium.org/1452673002 .

2 files changed, 11 insertions, 9 deletions

diff --git a/core/src/fpdftext/fpdf_text.cpp b/core/src/fpdftext/fpdf_text.cpp
index 55ab483722..0b7a849c75 100644
--- a/core/src/fpdftext/fpdf_text.cpp
+++ b/core/src/fpdftext/fpdf_text.cpp
@@ -14,6 +14,9 @@
 #include "third_party/base/nonstd_unique_ptr.h"
 #include "txtproc.h"
 
+#include <cctype>
+#include <cwctype>
+
 CFX_ByteString CharFromUnicodeAlt(FX_WCHAR unicode,
                                   int destcp,
                                   const FX_CHAR* defchar) {
@@ -436,10 +439,9 @@ void NormalizeString(CFX_WideString& str) {
 static FX_BOOL IsNumber(CFX_WideString& str) {
   for (int i = 0; i < str.GetLength(); i++) {
     FX_WCHAR ch = str[i];
-    if ((ch < '0' || ch > '9') && ch != '-' && ch != '+' && ch != '.' &&
-        ch != ' ') {
+    // TODO(dsinclair): --.+ +.-- should probably not be a number.
+    if (!std::iswdigit(ch) && ch != '-' && ch != '+' && ch != '.' && ch != ' ')
       return FALSE;
-    }
   }
   return TRUE;
 }
diff --git a/core/src/fpdftext/fpdf_text_int.cpp b/core/src/fpdftext/fpdf_text_int.cpp
index f02ca41e1a..0754757940 100644
--- a/core/src/fpdftext/fpdf_text_int.cpp
+++ b/core/src/fpdftext/fpdf_text_int.cpp
@@ -4,7 +4,8 @@
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
-#include <ctype.h>
+#include <cctype>
+#include <cwctype>
 #include <algorithm>
 
 #include "core/include/fpdfapi/fpdf_module.h"
@@ -2446,8 +2447,8 @@ void CPDF_TextPageFind::ExtractFindWhat(const CFX_WideString& findwhat) {
 FX_BOOL CPDF_TextPageFind::IsMatchWholeWord(const CFX_WideString& csPageText,
                                             int startPos,
                                             int endPos) {
-  int char_left = 0;
-  int char_right = 0;
+  FX_WCHAR char_left = 0;
+  FX_WCHAR char_right = 0;
   int char_count = endPos - startPos + 1;
   if (char_count < 1) {
     return FALSE;
@@ -2463,12 +2464,11 @@ FX_BOOL CPDF_TextPageFind::IsMatchWholeWord(const CFX_WideString& csPageText,
   }
   if ((char_left > 'A' && char_left < 'a') ||
       (char_left > 'a' && char_left < 'z') ||
-      (char_left > 0xfb00 && char_left < 0xfb06) ||
-      (char_left >= '0' && char_left <= '9') ||
+      (char_left > 0xfb00 && char_left < 0xfb06) || std::iswdigit(char_left) ||
       (char_right > 'A' && char_right < 'a') ||
       (char_right > 'a' && char_right < 'z') ||
       (char_right > 0xfb00 && char_right < 0xfb06) ||
-      (char_right >= '0' && char_right <= '9')) {
+      std::iswdigit(char_right)) {
     return FALSE;
   }
   if (!(('A' > char_left || char_left > 'Z') &&