Fix CPDF_InterForm::CheckRequiredFields and its callers.

The method is used twice in fpdfsdk/cpdfsdk_interform.cpp and twice in
fpdfsdk/javascript/Document.cpp, but not in a compatible way. Changed
the method so that it now returns true when checks pass, which is the
more natural thing to do, considering the name of the method.

BUG=pdfium:659

Change-Id: Iacf3049f328df1d4db3fbfc995acf184230ebf48
Reviewed-on: https://pdfium-review.googlesource.com/2297
Commit-Queue: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

4 files changed, 19 insertions, 18 deletions

diff --git a/core/fpdfdoc/cpdf_formfield.cpp b/core/fpdfdoc/cpdf_formfield.cpp
index b344327adc..b4aa90e2be 100644
--- a/core/fpdfdoc/cpdf_formfield.cpp
+++ b/core/fpdfdoc/cpdf_formfield.cpp
@@ -31,10 +31,6 @@ const int kFormListMultiSelect = 0x100;
 
 const int kFormComboEdit = 0x100;
 
-const int kFormFieldReadOnly = 0x01;
-const int kFormFieldRequired = 0x02;
-const int kFormFieldNoExport = 0x04;
-
 const int kFormRadioNoToggleOff = 0x100;
 const int kFormRadioUnison = 0x200;
 
@@ -108,12 +104,12 @@ void CPDF_FormField::SyncFieldFlags() {
                        ? FPDF_GetFieldAttr(m_pDict, "Ff")->GetInteger()
                        : 0;
   m_Flags = 0;
-  if (flags & 1)
-    m_Flags |= kFormFieldReadOnly;
-  if (flags & 2)
-    m_Flags |= kFormFieldRequired;
-  if (flags & 4)
-    m_Flags |= kFormFieldNoExport;
+  if (flags & FORMFLAG_READONLY)
+    m_Flags |= FORMFLAG_READONLY;
+  if (flags & FORMFLAG_REQUIRED)
+    m_Flags |= FORMFLAG_REQUIRED;
+  if (flags & FORMFLAG_NOEXPORT)
+    m_Flags |= FORMFLAG_NOEXPORT;
 
   if (type_name == "Btn") {
     if (flags & 0x8000) {
diff --git a/core/fpdfdoc/cpdf_formfield.h b/core/fpdfdoc/cpdf_formfield.h
index 9a1ddc4599..42608b1122 100644
--- a/core/fpdfdoc/cpdf_formfield.h
+++ b/core/fpdfdoc/cpdf_formfield.h
@@ -25,6 +25,10 @@
 #define FIELDTYPE_TEXTFIELD 6
 #define FIELDTYPE_SIGNATURE 7
 
+#define FORMFLAG_READONLY 0x01
+#define FORMFLAG_REQUIRED 0x02
+#define FORMFLAG_NOEXPORT 0x04
+
 class CPDF_Dictionary;
 class CPDF_Font;
 class CPDF_FormControl;
diff --git a/core/fpdfdoc/cpdf_interform.cpp b/core/fpdfdoc/cpdf_interform.cpp
index 6cffea6222..127e542227 100644
--- a/core/fpdfdoc/cpdf_interform.cpp
+++ b/core/fpdfdoc/cpdf_interform.cpp
@@ -1157,7 +1157,7 @@ CPDF_FormControl* CPDF_InterForm::AddControl(CPDF_FormField* pField,
   return pControl;
 }
 
-CPDF_FormField* CPDF_InterForm::CheckRequiredFields(
+bool CPDF_InterForm::CheckRequiredFields(
     const std::vector<CPDF_FormField*>* fields,
     bool bIncludeOrExclude) const {
   size_t nCount = m_pFieldTree->m_Root.CountFields();
@@ -1173,7 +1173,7 @@ CPDF_FormField* CPDF_InterForm::CheckRequiredFields(
     }
     uint32_t dwFlags = pField->GetFieldFlags();
     // TODO(thestig): Look up these magic numbers and add constants for them.
-    if (dwFlags & 0x04)
+    if (dwFlags & FORMFLAG_NOEXPORT)
       continue;
 
     bool bFind = true;
@@ -1181,11 +1181,13 @@ CPDF_FormField* CPDF_InterForm::CheckRequiredFields(
       bFind = pdfium::ContainsValue(*fields, pField);
     if (bIncludeOrExclude == bFind) {
       CPDF_Dictionary* pFieldDict = pField->m_pDict;
-      if ((dwFlags & 0x02) != 0 && pFieldDict->GetStringFor("V").IsEmpty())
-        return pField;
+      if ((dwFlags & FORMFLAG_REQUIRED) != 0 &&
+          pFieldDict->GetStringFor("V").IsEmpty()) {
+        return false;
+      }
     }
   }
-  return nullptr;
+  return true;
 }
 
 std::unique_ptr<CFDF_Document> CPDF_InterForm::ExportToFDF(
diff --git a/core/fpdfdoc/cpdf_interform.h b/core/fpdfdoc/cpdf_interform.h
index b846973435..a42c4cef84 100644
--- a/core/fpdfdoc/cpdf_interform.h
+++ b/core/fpdfdoc/cpdf_interform.h
@@ -69,9 +69,8 @@ class CPDF_InterForm {
   CPDF_DefaultAppearance GetDefaultAppearance() const;
   int GetFormAlignment() const;
 
-  CPDF_FormField* CheckRequiredFields(
-      const std::vector<CPDF_FormField*>* fields,
-      bool bIncludeOrExclude) const;
+  bool CheckRequiredFields(const std::vector<CPDF_FormField*>* fields,
+                           bool bIncludeOrExclude) const;
 
   std::unique_ptr<CFDF_Document> ExportToFDF(const CFX_WideStringC& pdf_path,
                                              bool bSimpleFileSpec) const;