Clean up more XFA code which causes warnings

This is part of efforts to bring XFA to chromium_code standard.
Most of them will have behavior change.
The details of these problems are:

xfa/fgas/layout/fgas_rtfbreak.cpp:
  Wrong condition with misused variable
xfa/fgas/localization/fgas_locale.cpp
  Unnecessary condition
xfa/fxbarcode/datamatrix/BC_DataMatrixDecodedBitStreamParser.cpp
xfa/fxfa/app/xfa_fffield.cpp
  Unreachable code should be the correct code
xfa/fxbarcode/pdf417/BC_PDF417ScanningDecoder.cpp
xfa/fxbarcode/qrcode/BC_QRDetector.cpp
  Wrong condition logic

BUG=pdfium:29

Review-Url: https://codereview.chromium.org/2000073003

3 files changed, 15 insertions, 15 deletions

diff --git a/xfa/fxbarcode/datamatrix/BC_DataMatrixDecodedBitStreamParser.cpp b/xfa/fxbarcode/datamatrix/BC_DataMatrixDecodedBitStreamParser.cpp
index 53c5a84656..292a1de2f7 100644
--- a/xfa/fxbarcode/datamatrix/BC_DataMatrixDecodedBitStreamParser.cpp
+++ b/xfa/fxbarcode/datamatrix/BC_DataMatrixDecodedBitStreamParser.cpp
@@ -246,7 +246,7 @@ void CBC_DataMatrixDecodedBitStreamParser::DecodeC40Segment(
           shift = 0;
           break;
         default:
-          break;
+          // Should never be reached.
           e = BCExceptionFormatException;
           return;
       }
@@ -337,7 +337,7 @@ void CBC_DataMatrixDecodedBitStreamParser::DecodeTextSegment(
           }
           break;
         default:
-          break;
+          // Should never be reached.
           e = BCExceptionFormatException;
           return;
       }
diff --git a/xfa/fxbarcode/pdf417/BC_PDF417ScanningDecoder.cpp b/xfa/fxbarcode/pdf417/BC_PDF417ScanningDecoder.cpp
index 4c3d4dbdf2..4e1d8dd1e9 100644
--- a/xfa/fxbarcode/pdf417/BC_PDF417ScanningDecoder.cpp
+++ b/xfa/fxbarcode/pdf417/BC_PDF417ScanningDecoder.cpp
@@ -423,15 +423,13 @@ CBC_PDF417ScanningDecoder::createDecoderResultFromAmbiguousValues(
     }
     CBC_CommonDecoderResult* decoderResult =
         decodeCodewords(codewords, ecLevel, erasureArray, e);
-    if (e != BCExceptionNO) {
-      e = BCExceptionNO;
-      continue;
-    } else {
+    if (e == BCExceptionNO)
       return decoderResult;
-    }
+
+    e = BCExceptionNO;
     if (ambiguousIndexCount.GetSize() == 0) {
       e = BCExceptionChecksumInstance;
-      return NULL;
+      return nullptr;
     }
     for (int32_t i = 0; i < ambiguousIndexCount.GetSize(); i++) {
       if (ambiguousIndexCount[i] <
@@ -442,7 +440,7 @@ CBC_PDF417ScanningDecoder::createDecoderResultFromAmbiguousValues(
         ambiguousIndexCount[i] = 0;
         if (i == ambiguousIndexCount.GetSize() - 1) {
           e = BCExceptionChecksumInstance;
-          return NULL;
+          return nullptr;
         }
       }
     }
diff --git a/xfa/fxbarcode/qrcode/BC_QRDetector.cpp b/xfa/fxbarcode/qrcode/BC_QRDetector.cpp
index 15ae3e26f1..35915cd673 100644
--- a/xfa/fxbarcode/qrcode/BC_QRDetector.cpp
+++ b/xfa/fxbarcode/qrcode/BC_QRDetector.cpp
@@ -56,17 +56,17 @@ CBC_QRDetectorResult* CBC_QRDetector::ProcessFinderPatternInfo(
       CalculateModuleSize(topLeft.get(), topRight.get(), bottomLeft.get());
   if (moduleSize < 1.0f) {
     e = BCExceptionRead;
-    BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+    return nullptr;
   }
   int32_t dimension = ComputeDimension(topLeft.get(), topRight.get(),
                                        bottomLeft.get(), moduleSize, e);
-  BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+  BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
   CBC_QRCoderVersion* provisionalVersion =
       CBC_QRCoderVersion::GetProvisionalVersionForDimension(dimension, e);
-  BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+  BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
   int32_t modulesBetweenFPCenters =
       provisionalVersion->GetDimensionForVersion() - 7;
-  CBC_QRAlignmentPattern* alignmentPattern = NULL;
+  CBC_QRAlignmentPattern* alignmentPattern = nullptr;
   if (provisionalVersion->GetAlignmentPatternCenters()->GetSize() > 0) {
     FX_FLOAT bottomRightX =
         topRight->GetX() - topLeft->GetX() + bottomLeft->GetX();
@@ -83,8 +83,10 @@ CBC_QRDetectorResult* CBC_QRDetector::ProcessFinderPatternInfo(
     for (int32_t i = 4; i <= 16; i <<= 1) {
       CBC_QRAlignmentPattern* temp = FindAlignmentInRegion(
           moduleSize, estAlignmentX, estAlignmentY, (FX_FLOAT)i, e);
-      alignmentPattern = temp;
-      break;
+      if (temp) {
+        alignmentPattern = temp;
+        break;
+      }
     }
   }
   CBC_CommonBitMatrix* bits =