BUG: remove overly optimistic short-cut when reading BCs

- had an optimisation to skip attempted reading for zero-sized
  patches. But this leads to inconsistency in the code branching, thus
  removing it.

src/OpenFOAM/fields/pointPatchFields/basic/value/valuePointPatchField.C

@@ -38,10 +38,8 @@ bool Foam::valuePointPatchField<Type>::readValueEntry
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = pointPatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = pointPatchFieldBase::patch();
 
 
     const auto* eptr = dict.findEntry("value", keyType::LITERAL);

src/finiteArea/fields/faPatchFields/basic/mixed/mixedFaPatchField.C

@@ -37,10 +37,8 @@ bool Foam::mixedFaPatchField<Type>::readMixedEntries
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = faPatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = faPatchFieldBase::patch();
 
 
     // If there is a 'refValue', also require all others

src/finiteArea/fields/faPatchFields/faPatchField/faPatchField.C

@@ -39,10 +39,8 @@ bool Foam::faPatchField<Type>::readValueEntry
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = faPatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = faPatchFieldBase::patch();
 
 
     const auto* eptr = dict.findEntry("value", keyType::LITERAL);

src/finiteArea/fields/faePatchFields/faePatchField/faePatchField.C

@@ -38,10 +38,8 @@ bool Foam::faePatchField<Type>::readValueEntry
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = faePatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = faePatchFieldBase::patch();
 
 
     const auto* eptr = dict.findEntry("value", keyType::LITERAL);

src/finiteVolume/fields/fvPatchFields/basic/mixed/mixedFvPatchField.C

@@ -37,10 +37,8 @@ bool Foam::mixedFvPatchField<Type>::readMixedEntries
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = fvPatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = fvPatchFieldBase::patch();
 
 
     // If there is a 'refValue', also require all others

src/finiteVolume/fields/fvPatchFields/fvPatchField/fvPatchField.C

@@ -41,10 +41,8 @@ bool Foam::fvPatchField<Type>::readValueEntry
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = fvPatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = fvPatchFieldBase::patch();
 
 
     const auto* eptr = dict.findEntry("value", keyType::LITERAL);

src/finiteVolume/fields/fvsPatchFields/fvsPatchField/fvsPatchField.C

@@ -41,10 +41,8 @@ bool Foam::fvsPatchField<Type>::readValueEntry
     IOobjectOption::readOption readOpt
 )
 {
-    const auto& p = fvsPatchFieldBase::patch();
-
-    if (!p.size()) return true;  // Can be exceptionally lazy
     if (!IOobjectOption::isAnyRead(readOpt)) return false;
+    const auto& p = fvsPatchFieldBase::patch();
 
 
     const auto* eptr = dict.findEntry("value", keyType::LITERAL);