Replace raw value for constant error value in string operations

Currently Find() and other methods that return a FX_STRSIZE return -1
to indicate error/failure. This means that there is a lot of magic
numbers and magic checks floating around. The standard library for
similar operations uses a npos constant. This CL implements
FX_STRNPOS, and replaces usages of magic number checking. It also does
some type cleanup along the way where it was obvious that FX_STRSIZE
should be being used.

Removing the magic numbers should make eventually changing FX_STRSIZE
to be unsigned easier in the future.

BUG=pdfium:828

Change-Id: I67e481e44cf2f75a1698afa8fbee4f375a74c490
Reviewed-on: https://pdfium-review.googlesource.com/9651
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator_unittest.cpp b/core/fpdfapi/edit/cpdf_pagecontentgenerator_unittest.cpp
index 62b10c9149..e9676b1115 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator_unittest.cpp
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator_unittest.cpp
@@ -186,8 +186,10 @@ TEST_F(CPDF_PageContentGeneratorTest, ProcessStandardText) {
   std::ostringstream buf;
   TestProcessText(&generator, &buf, pTextObj.get());
   CFX_ByteString textString(buf);
-  int firstResourceAt = textString.Find('/') + 1;
-  int secondResourceAt = textString.ReverseFind('/') + 1;
+  FX_STRSIZE firstResourceAt = textString.Find('/') + 1;
+  FX_STRSIZE secondResourceAt = textString.ReverseFind('/') + 1;
+  EXPECT_NE(FX_STRNPOS, firstResourceAt);
+  EXPECT_NE(FX_STRNPOS, secondResourceAt);
   CFX_ByteString firstString = textString.Left(firstResourceAt);
   CFX_ByteString midString =
       textString.Mid(firstResourceAt, secondResourceAt - firstResourceAt);
@@ -252,7 +254,8 @@ TEST_F(CPDF_PageContentGeneratorTest, ProcessText) {
   }
 
   CFX_ByteString textString(buf);
-  int firstResourceAt = textString.Find('/') + 1;
+  FX_STRSIZE firstResourceAt = textString.Find('/') + 1;
+  EXPECT_NE(FX_STRNPOS, firstResourceAt);
   CFX_ByteString firstString = textString.Left(firstResourceAt);
   CFX_ByteString lastString =
       textString.Right(textString.GetLength() - firstResourceAt);