Revert "Revert "Add possibility to filter out invalid keys""

This reverts commit aeb2f056 but
does it in a way that it still works with older GPGME Versions.

src/kleo/defaultkeyfilter.cpp

@@ -47,6 +47,7 @@ public:
         mIsOpenPGP(DoesNotMatter),
         mWasValidated(DoesNotMatter),
         mIsDeVs(DoesNotMatter),
+        mBad(DoesNotMatter),
         mOwnerTrust(LevelDoesNotMatter),
         mOwnerTrustReferenceLevel(Key::Unknown),
         mValidity(LevelDoesNotMatter),
@@ -78,6 +79,7 @@ public:
     TriState mIsOpenPGP;
     TriState mWasValidated;
     TriState mIsDeVs;
+    TriState mBad;
 
     LevelState mOwnerTrust;
     GpgME::Key::OwnerTrust mOwnerTrustReferenceLevel;
@@ -135,6 +137,11 @@ bool DefaultKeyFilter::matches(const Key &key, MatchContexts contexts) const
             bool(Formatting::uidsHaveFullValidity(key) && Formatting::isKeyDeVs(key)) != bool(d_ptr->mIsDeVs == Set)) {
         return false;
     }
+    if (d_ptr->mBad != DoesNotMatter &&
+        /* This is similar to GPGME::Key::isBad which was introduced in GPGME 1.13.0 */
+        bool(key.isNull() || key.isRevoked() || key.isExpired() || key.isDisabled() || key.isInvalid()) != bool(d_ptr->mBad == Set)) {
+        return false;
+    }
     switch (d_ptr->mOwnerTrust) {
     default:
     case LevelDoesNotMatter:
@@ -348,6 +355,11 @@ void DefaultKeyFilter::setIsDeVs(DefaultKeyFilter::TriState value) const
     d_ptr->mIsDeVs = value;
 }
 
+void DefaultKeyFilter::setIsBad(DefaultKeyFilter::TriState value) const
+{
+    d_ptr->mBad = value;
+}
+
 QColor DefaultKeyFilter::fgColor() const
 {
     return d_ptr->mFgColor;
@@ -497,3 +509,8 @@ DefaultKeyFilter::TriState DefaultKeyFilter::isDeVS() const
 {
     return d_ptr->mIsDeVs;
 }
+
+DefaultKeyFilter::TriState DefaultKeyFilter::isBad() const
+{
+    return d_ptr->mBad;
+}

src/kleo/defaultkeyfilter.h

@@ -87,6 +87,7 @@ public:
     TriState isOpenPGP() const;
     TriState wasValidated() const;
     TriState isDeVS() const;
+    TriState isBad() const;
 
     LevelState ownerTrust() const;
     GpgME::Key::OwnerTrust ownerTrustReferenceLevel() const;
@@ -112,6 +113,7 @@ public:
     void setIsOpenPGP(const TriState) const;
     void setWasValidated(const TriState) const;
     void setIsDeVs(const TriState) const;
+    void setIsBad(const TriState) const;
 
     void setOwnerTrust(const LevelState) const;
     void setOwnerTrustReferenceLevel(const GpgME::Key::OwnerTrust) const;