StanzaError: Add NoType and NoCondition for -1 values

Previsously static_cast<QXmppStanza::Error::Condition>(-1) was used when
no condition was set (or type). This adds real enum values with that
integer value to avoid undefined behaviour.

Fixes #495.

2 files changed, 8 insertions, 7 deletions

diff --git a/src/base/QXmppStanza.cpp b/src/base/QXmppStanza.cpp
index e7cb0208..fa170740 100644
--- a/src/base/QXmppStanza.cpp
+++ b/src/base/QXmppStanza.cpp
@@ -399,12 +399,12 @@ void QXmppStanza::Error::setCode(int code)
 /// The conditions QXmppStanza::Error::Gone and QXmppStanza::Error::Redirect
 /// can be used in combination with redirectUri().
 ///
-/// \warning Due to compatibility this returns \c Condition(-1) when no
-/// condition is set. When possible you should use conditionOpt().
+/// \warning This returns NoCondition when no condition is set. When possible you should use
+/// conditionOpt().
 ///
 QXmppStanza::Error::Condition QXmppStanza::Error::condition() const
 {
-    return d->condition.value_or(QXmppStanza::Error::Condition(-1));
+    return d->condition.value_or(NoCondition);
 }
 
 ///
@@ -426,7 +426,7 @@ auto QXmppStanza::Error::conditionOpt() const -> std::optional<Condition>
 /// The conditions QXmppStanza::Error::Gone and QXmppStanza::Error::Redirect
 /// can be used in combination with setRedirectUri().
 ///
-void QXmppStanza::Error::setCondition(QXmppStanza::Error::Condition cond)
+void QXmppStanza::Error::setCondition(Condition cond)
 {
     if (int(cond) < 0) {
         d->condition = std::nullopt;
@@ -451,12 +451,11 @@ void QXmppStanza::Error::setCondition(std::optional<Condition> cond)
 ///
 /// Returns the type of the error.
 ///
-/// \warning Due to compatibility this returns \c Type(-1) when no type is set.
-/// When possible you should use typeOpt().
+/// \warning This returns NoType when no type is set. When possible you should use typeOpt().
 ///
 QXmppStanza::Error::Type QXmppStanza::Error::type() const
 {
-    return d->type.value_or(QXmppStanza::Error::Type(-1));
+    return d->type.value_or(NoType);
 }
 
 ///
diff --git a/src/base/QXmppStanza.h b/src/base/QXmppStanza.h
index 394bc6c6..320bab26 100644
--- a/src/base/QXmppStanza.h
+++ b/src/base/QXmppStanza.h
@@ -98,6 +98,7 @@ public:
         /// The error descriptions are not detailed in here. The exact meaning
         /// can be found in the particular protocols using them.
         enum Type {
+            NoType = -1,
             Cancel,    ///< The error is not temporary.
             Continue,  ///< The error was only a warning.
             Modify,    ///< The request needs to be changed and resent.
@@ -107,6 +108,7 @@ public:
 
         /// A detailed condition of the error
         enum Condition {
+            NoCondition = -1,
             BadRequest,             ///< The request does not contain a valid schema.
             Conflict,               ///< The request conflicts with another.
             FeatureNotImplemented,  ///< The feature is not implemented.