[libcalamares] Distinguish kinds of errors

- errors can now carry an integer what-am-I code apart from
   the message; all errors have a code != 0 (and ok has code 0).

src/libcalamares/Job.cpp

@@ -21,16 +21,16 @@
 namespace Calamares
 {
 
-JobResult::JobResult( JobResult&& rhs ) :
-      m_ok( rhs.m_ok )
-    , m_message( std::move( rhs.m_message ) )
+JobResult::JobResult( JobResult&& rhs )
+    : m_message( std::move( rhs.m_message ) )
     , m_details( std::move( rhs.m_details ) )
+    , m_number( rhs.m_number )
 {
 }
 
 JobResult::operator bool() const
 {
-    return m_ok;
+    return m_number == 0;
 }
 
 
@@ -64,21 +64,26 @@ JobResult::setDetails( const QString& details )
 JobResult
 JobResult::ok()
 {
-    return JobResult( true, QString(), QString() );
+    return JobResult( QString(), QString(), NoError );
 }
 
 
 JobResult
 JobResult::error( const QString& message, const QString& details )
 {
-    return JobResult( false, message, details );
+    return JobResult( message, details, -1 );
 }
 
+JobResult
+JobResult::internalError( const QString& message, const QString& details, int number )
+{
+    return JobResult( message, details, number ? number : GenericError );
+}
 
-JobResult::JobResult( bool ok, const QString& message, const QString& details )
-    : m_ok( ok )
-    , m_message( message )
+JobResult::JobResult( const QString& message, const QString& details, int number )
+    : m_message( message )
     , m_details( details )
+    , m_number( number )
 {}
 
 

src/libcalamares/Job.h

@@ -29,6 +29,13 @@ namespace Calamares {
 class DLLEXPORT JobResult
 {
 public:
+    enum
+    {
+        NoError = 0,
+        GenericError = -1,
+        PythonUncaughtException = 1
+    } ;
+
     JobResult( const JobResult& rhs ) = delete;
     JobResult( JobResult&& rhs );
 
@@ -42,17 +49,20 @@ public:
     virtual QString details() const;
     virtual void setDetails( const QString& details );
 
+    /// @brief an "ok status" result
     static JobResult ok();
-
+    /// @brief an "error" result resulting from the execution of the job
     static JobResult error( const QString& message, const QString& details = QString() );
+    /// @brief an "internal error" meaning the job itself has a problem (usually for python)
+    static JobResult internalError( const QString&, const QString& details, int errorCode );
 
 protected:
-    explicit JobResult( bool ok, const QString& message, const QString& details );
+    explicit JobResult( const QString& message, const QString& details, int errorCode );
 
 private:
-    bool m_ok;
     QString m_message;
     QString m_details;
+    int m_number;
 };
 
 class DLLEXPORT Job : public QObject

src/libcalamares/PythonJob.cpp

@@ -373,8 +373,10 @@ PythonJob::exec()
         }
         bp::handle_exception();
         PyErr_Clear();
-        return JobResult::error( tr( "Boost.Python error in job \"%1\"." ).arg( prettyName() ),
-                                 msg );
+        return JobResult::internalError(
+                    tr( "Boost.Python error in job \"%1\"." ).arg( prettyName() ),
+                    msg,
+                    JobResult::PythonUncaughtException );
     }
 }
 

src/libcalamaresui/viewpages/PythonQtJob.h

@@ -36,7 +36,7 @@ public:
                                 const QString& message,
                                 const QString& details )
         : QObject( nullptr )
-        , Calamares::JobResult( ok, message, details )
+        , Calamares::JobResult( message, details, ok ? 0 : Calamares::JobResult::GenericError )
     {}
 };