Make a couple small improvements to CPDF_FormField.

- Reduce the scope of a variable in ResetField().
- Replace a pointer in ResetField() with a bool.
- Remove a redundant call in GetValue().

Change-Id: I69e82c3e4c3d47fda48f3bb5ad0bfca4a08ca6d6
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/59940
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

core/fpdfdoc/cpdf_formfield.cpp

diff --git a/core/fpdfdoc/cpdf_formfield.cpp b/core/fpdfdoc/cpdf_formfield.cpp
index 80fa65d..ff99ee6 100644
--- a/core/fpdfdoc/cpdf_formfield.cpp
+++ b/core/fpdfdoc/cpdf_formfield.cpp
@@ -180,14 +180,17 @@
       if (pDV)
         csDValue = pDV->GetUnicodeText();
 
-      const CPDF_Object* pV =
-          FPDF_GetFieldAttr(m_pDict.Get(), pdfium::form_fields::kV);
       WideString csValue;
-      if (pV)
-        csValue = pV->GetUnicodeText();
+      {
+        // Limit the scope of |pV| because it may get invalidated below.
+        const CPDF_Object* pV =
+            FPDF_GetFieldAttr(m_pDict.Get(), pdfium::form_fields::kV);
+        if (pV)
+          csValue = pV->GetUnicodeText();
+      }
 
-      const CPDF_Object* pRV = FPDF_GetFieldAttr(m_pDict.Get(), "RV");
-      if (!pRV && (csDValue == csValue))
+      bool bHasRV = !!FPDF_GetFieldAttr(m_pDict.Get(), "RV");
+      if (!bHasRV && (csDValue == csValue))
         return false;
 
       if (notify == NotificationOption::kNotify &&
@@ -200,7 +203,7 @@
           return false;
 
         m_pDict->SetFor(pdfium::form_fields::kV, std::move(pClone));
-        if (pRV) {
+        if (bHasRV) {
           m_pDict->SetFor("RV", pDV->Clone());
         }
       } else {
@@ -296,12 +299,8 @@
       FPDF_GetFieldAttr(m_pDict.Get(), bDefault ? pdfium::form_fields::kDV
                                                 : pdfium::form_fields::kV);
   if (!pValue) {
-    if (!bDefault) {
-      if (m_Type == kRichText)
-        pValue = FPDF_GetFieldAttr(m_pDict.Get(), pdfium::form_fields::kV);
-      if (!pValue && m_Type != kText)
-        pValue = FPDF_GetFieldAttr(m_pDict.Get(), pdfium::form_fields::kDV);
-    }
+    if (!bDefault && m_Type != kText)
+      pValue = FPDF_GetFieldAttr(m_pDict.Get(), pdfium::form_fields::kDV);
     if (!pValue)
       return WideString();
   }