Add wxSizerFlags::DisableConsistencyChecks()

This allows to (hopefully temporarily) disable size flag check asserts.

docs/changes.txt

@@ -25,7 +25,9 @@ Changes in behaviour not resulting in compilation errors
   (it used to succeed in wxMSW).
 
 - Using invalid flags with wxBoxSizer or wxGridSizer items now triggers asserts
-  when done from the code or error messages when done in XRC.
+  when done from the code or error messages when done in XRC. These asserts are
+  best avoided by fixing the flags, but wxSizerFlags::DisableConsistencyChecks()
+  can be used to globally suppress them until this can be done.
 
 - wxWS_EX_VALIDATE_RECURSIVELY is now the default behaviour, i.e. calling
   Validate() or TransferData{From,To}Window() will now also call the same

include/wx/sizer.h

@@ -238,6 +238,9 @@ public:
     int GetFlags() const { return m_flags; }
     int GetBorderInPixels() const { return m_borderInPixels; }
 
+    // Disablee sizer flags (in)consistency asserts.
+    static void DisableConsistencyChecks();
+
 private:
 #ifdef wxNEEDS_BORDER_IN_PX
     static float DoGetDefaultBorderInPx();

interface/wx/sizer.h

@@ -1480,6 +1480,29 @@ public:
      */
     wxSizerFlags& CentreVertical();
 
+    /**
+        Globally disable checks for sizer flag consistency in debug builds.
+
+        By default, sizer classes such as wxBoxSizer and wxFlexGridSizer assert
+        when passed invalid flags, even though doing this usually doesn't
+        result in any catastrophic consequences and the invalid flags are
+        simply ignored later. Due to this, and the fact that these checks were
+        only added in wxWidgets 3.1, existing code may run into multiple
+        asserts warning about incorrect sizer flags use. Using this function
+        provides a temporary solution for avoiding such asserts when upgrading
+        to wxWidgets 3.1 from a previous version and will prevent such checks
+        from being done.
+
+        Please do note that correcting the code by removing the invalid flags
+        remains a much better solution as these asserts may be very helpful to
+        understand why some code using sizer flags doesn't work as expected, so
+        using this function, especially permanently, rather than a temporary
+        workaround, is @e not recommended.
+
+        @since 3.1.6
+     */
+    static void DisableConsistencyChecks();
+
     /**
         Sets the border in the given @a direction having twice the default
         border size.

src/common/sizer.cpp

@@ -147,6 +147,8 @@ static const int SIZER_FLAGS_MASK =
 namespace
 {
 
+bool gs_disableFlagChecks = false;
+
 wxString MakeFlagsCheckMessage(const char* start, const char* whatToRemove)
 {
     return wxString::Format
@@ -158,7 +160,9 @@ wxString MakeFlagsCheckMessage(const char* start, const char* whatToRemove)
              "reporting the problem to the program developers.\n"
              "\n"
              "If you're the developer, simply remove %s from your code to "
-             "avoid getting this message.\n",
+             "avoid getting this message. You can also call "
+             "wxSizerFlags::DisableConsistencyChecks() to globally disable "
+             "all such checks, but this is strongly not recommended.",
              start,
              whatToRemove
            );
@@ -171,7 +175,7 @@ wxString MakeFlagsCheckMessage(const char* start, const char* whatToRemove)
 #define ASSERT_NO_IGNORED_FLAGS_IMPL(f, value, name, explanation) \
     wxASSERT_MSG                                                  \
     (                                                             \
-      !((f) & (value)),                                           \
+      gs_disableFlagChecks || !((f) & (value)),                   \
       MakeFlagsCheckMessage                                       \
       (                                                           \
         name " will be ignored in this sizer: " explanation,      \
@@ -185,7 +189,7 @@ wxString MakeFlagsCheckMessage(const char* start, const char* whatToRemove)
 #define ASSERT_INCOMPATIBLE_NOT_USED_IMPL(f, f1, n1, f2, n2)       \
     wxASSERT_MSG                                                   \
     (                                                              \
-      ((f) & (f1 | f2)) != (f1 | f2),                              \
+      gs_disableFlagChecks || ((f) & (f1 | f2)) != (f1 | f2),      \
       MakeFlagsCheckMessage                                        \
       (                                                            \
         "One of " n1 " and " n2 " will be ignored in this sizer: " \
@@ -203,6 +207,14 @@ wxString MakeFlagsCheckMessage(const char* start, const char* whatToRemove)
     ASSERT_INCOMPATIBLE_NOT_USED(f, wxALIGN_CENTRE_VERTICAL, wxALIGN_BOTTOM)
 
 
+/* static */
+void wxSizerFlags::DisableConsistencyChecks()
+{
+#if wxDEBUG_LEVEL
+    gs_disableFlagChecks = true;
+#endif // wxDEBUG_LEVEL
+}
+
 void wxSizerItem::Init(const wxSizerFlags& flags)
 {
     Init();
@@ -1515,7 +1527,8 @@ wxSizerItem *wxGridSizer::DoInsert(size_t index, wxSizerItem *item)
         // Check that expansion will happen in at least one of the directions.
         wxASSERT_MSG
         (
-            !(flags & (wxALIGN_BOTTOM | wxALIGN_CENTRE_VERTICAL)) ||
+            gs_disableFlagChecks ||
+              !(flags & (wxALIGN_BOTTOM | wxALIGN_CENTRE_VERTICAL)) ||
                 !(flags & (wxALIGN_RIGHT | wxALIGN_CENTRE_HORIZONTAL)),
             MakeFlagsCheckMessage
             (