Dealing with inconsistent wxGLCanvas::IsDisplaySupported()

wxGLCanvas::IsDisplaySupported() handles wxGL_{MINOR,MAJOR}_VERSION
attributes only in 3.0.4. Since 3.1.0 the attributes are apparently not
supported, so instead wxGLContext::IsOK() is used (introduced in 3.1.0).

Fixes: lp:1775995
* https://bugs.launchpad.net/kicad/+bug/1775995

common/gal/opengl/opengl_gal.cpp

@@ -73,7 +73,9 @@ OPENGL_GAL::OPENGL_GAL( GAL_DISPLAY_OPTIONS& aDisplayOptions, wxWindow* aParent,
     mouseListener( aMouseListener ), paintListener( aPaintListener ), currentManager( nullptr ),
     cachedManager( nullptr ), nonCachedManager( nullptr ), overlayManager( nullptr ), mainBuffer( 0 ), overlayBuffer( 0 )
 {
-#if wxCHECK_VERSION( 3, 0, 3 )
+// IsDisplayAttr() handles WX_GL_{MAJOR,MINOR}_VERSION correctly only in 3.0.4
+// starting with 3.1.0 one should use wxGLContext::IsOk() (done by GL_CONTEXT_MANAGER)
+#if wxCHECK_VERSION( 3, 0, 3 ) and !wxCHECK_VERSION( 3, 1, 0 )
     const int attr[] = { WX_GL_MAJOR_VERSION, 2, WX_GL_MINOR_VERSION, 1, 0 };
 
     if( !IsDisplaySupported( attr ) )
@@ -83,12 +85,19 @@ OPENGL_GAL::OPENGL_GAL( GAL_DISPLAY_OPTIONS& aDisplayOptions, wxWindow* aParent,
     if( glMainContext == NULL )
     {
         glMainContext = GL_CONTEXT_MANAGER::Get().CreateCtx( this );
+
+        if( !glMainContext )
+            throw std::runtime_error( "Could not create the main OpenGL context" );
+
         glPrivContext = glMainContext;
         shader = new SHADER();
     }
     else
     {
         glPrivContext = GL_CONTEXT_MANAGER::Get().CreateCtx( this, glMainContext );
+
+        if( !glPrivContext )
+            throw std::runtime_error( "Could not create a private OpenGL context" );
     }
 
     ++instanceCounter;

common/gl_context_mgr.cpp

@@ -24,6 +24,7 @@
  */
 
 #include <gl_context_mgr.h>
+#include <wx/debug.h>
 
 GL_CONTEXT_MANAGER& GL_CONTEXT_MANAGER::Get()
 {
@@ -35,8 +36,16 @@ GL_CONTEXT_MANAGER& GL_CONTEXT_MANAGER::Get()
 wxGLContext* GL_CONTEXT_MANAGER::CreateCtx( wxGLCanvas* aCanvas, const wxGLContext* aOther )
 {
     wxGLContext* context = new wxGLContext( aCanvas, aOther );
-    assert( context /* && context->IsOK() */ );     // IsOK() is available in wx3.1+
-    assert( m_glContexts.count( context ) == 0 );
+    wxCHECK( context, nullptr );
+
+#if wxCHECK_VERSION( 3, 1, 0 )
+    if( !context->IsOK() )
+    {
+        delete context;
+        return nullptr;
+    }
+#endif /* wxCHECK_VERSION( 3, 1, 0 ) */
+
     m_glContexts.insert( std::make_pair( context, aCanvas ) );
 
     return context;
@@ -53,13 +62,11 @@ void GL_CONTEXT_MANAGER::DestroyCtx( wxGLContext* aContext )
     else
     {
         // Do not delete unknown GL contexts
-        assert( false );
+        wxFAIL;
     }
 
     if( m_glCtx == aContext )
-    {
         m_glCtx = NULL;
-    }
 }
 
 
@@ -78,7 +85,7 @@ void GL_CONTEXT_MANAGER::DeleteAll()
 
 void GL_CONTEXT_MANAGER::LockCtx( wxGLContext* aContext, wxGLCanvas* aCanvas )
 {
-    assert( aCanvas || m_glContexts.count( aContext ) > 0 );
+    wxCHECK( aCanvas || m_glContexts.count( aContext ) > 0, /* void */ );
 
     m_glCtxMutex.lock();
     wxGLCanvas* canvas = aCanvas ? aCanvas : m_glContexts.at( aContext );
@@ -97,7 +104,7 @@ void GL_CONTEXT_MANAGER::LockCtx( wxGLContext* aContext, wxGLCanvas* aCanvas )
 
 void GL_CONTEXT_MANAGER::UnlockCtx( wxGLContext* aContext )
 {
-    assert( m_glContexts.count( aContext ) > 0 );
+    wxCHECK( m_glContexts.count( aContext ) > 0, /* void */ );
 
     if( m_glCtx == aContext )
     {
@@ -106,9 +113,8 @@ void GL_CONTEXT_MANAGER::UnlockCtx( wxGLContext* aContext )
     }
     else
     {
-        wxLogDebug(
-            "Trying to unlock GL context mutex from a wrong context: aContext %p m_glCtx %p",
-            aContext, m_glCtx );
+        wxFAIL_MSG( wxString::Format( "Trying to unlock GL context mutex from "
+                    "a wrong context: aContext %p m_glCtx %p", aContext, m_glCtx ) );
     }
 }