Fix storing wxBitmap data in GdkPixbuf

Under wxGTK+2 bitmap data with mask and without it (raw) should be stored
in the separate GdkPixbuf buffers - just like it's done in wxGTK+3. These
two buffers are necessary because only GdkPixbuf with raw bitmap data
(original, non-masked) should be copied when wxBitmapRefData instance is
cloned e.g. in SetMask(). GdkPixbuf with masked data is not copied and is
created on first use in wxBitmap::GetPixbuf().

Closes #18508.
See #18498.

include/wx/gtk/bitmap.h

@@ -133,7 +133,6 @@ public:
 #endif
 
 #ifdef __WXGTK3__
-    GdkPixbuf* GetPixbufNoMask() const;
     cairo_t* CairoCreate() const;
     void Draw(cairo_t* cr, int x, int y, bool useMask = true, const wxColour* fg = NULL, const wxColour* bg = NULL) const;
     void SetSourceSurface(cairo_t* cr, int x, int y, const wxColour* fg = NULL, const wxColour* bg = NULL) const;
@@ -143,6 +142,7 @@ public:
     bool HasPixbuf() const;
     wxBitmap(GdkPixmap* pixmap);
 #endif
+    GdkPixbuf* GetPixbufNoMask() const;
     GdkPixbuf *GetPixbuf() const;
 
     // raw bitmap access support functions

src/gtk/bitmap.cpp

@@ -58,7 +58,6 @@ static void MaskToAlpha(GdkPixmap* mask, GdkPixbuf* pixbuf, int w, int h)
     {
         for (int x = w; x; x--, p += 4, mask_data += 3)
         {
-            *p = 255;
             // no need to test all 3 components,
             //   pixels are either (0,0,0) or (0xff,0xff,0xff)
             if (mask_data[0] == 0)
@@ -208,7 +207,7 @@ bool wxMask::InitFromColour(const wxBitmap& bitmap, const wxColour& colour)
         const wxByte r_mask = colour.Red();
         const wxByte g_mask = colour.Green();
         const wxByte b_mask = colour.Blue();
-        GdkPixbuf* pixbuf = bitmap.GetPixbuf();
+        GdkPixbuf* pixbuf = bitmap.GetPixbufNoMask();
         const wxByte* in = gdk_pixbuf_get_pixels(pixbuf);
         const int inc = 3 + int(gdk_pixbuf_get_has_alpha(pixbuf) != 0);
         const int rowpadding = gdk_pixbuf_get_rowstride(pixbuf) - inc * w;
@@ -333,7 +332,6 @@ public:
     virtual bool IsOk() const wxOVERRIDE;
 
 #ifdef __WXGTK3__
-    GdkPixbuf* m_pixbufMask;
     GdkPixbuf* m_pixbufNoMask;
     cairo_surface_t* m_surface;
     double m_scaleFactor;
@@ -341,6 +339,7 @@ public:
     GdkPixmap      *m_pixmap;
     GdkPixbuf      *m_pixbuf;
 #endif
+    GdkPixbuf      *m_pixbufMask;
     wxMask         *m_mask;
     int             m_width;
     int             m_height;
@@ -359,7 +358,6 @@ public:
 wxBitmapRefData::wxBitmapRefData(int width, int height, int depth)
 {
 #ifdef __WXGTK3__
-    m_pixbufMask = NULL;
     m_pixbufNoMask = NULL;
     m_surface = NULL;
     m_scaleFactor = 1;
@@ -367,6 +365,7 @@ wxBitmapRefData::wxBitmapRefData(int width, int height, int depth)
     m_pixmap = NULL;
     m_pixbuf = NULL;
 #endif
+    m_pixbufMask = NULL;
     m_mask = NULL;
     m_width = width;
     m_height = height;
@@ -384,13 +383,13 @@ wxBitmapRefData::wxBitmapRefData(int width, int height, int depth)
 wxBitmapRefData::~wxBitmapRefData()
 {
 #ifdef __WXGTK3__
-    if (m_pixbufMask)
-        g_object_unref(m_pixbufMask);
     if (m_pixbufNoMask)
         g_object_unref(m_pixbufNoMask);
     if (m_surface)
         cairo_surface_destroy(m_surface);
 #else
+    if (m_pixbufMask)
+        g_object_unref(m_pixbufMask);
     if (m_pixmap)
         g_object_unref (m_pixmap);
     if (m_pixbuf)
@@ -542,7 +541,6 @@ bool wxBitmap::Create( int width, int height, int depth )
     return true;
 }
 
-#ifdef __WXGTK3__
 static void CopyImageData(
     guchar* dst, int dstChannels, int dstStride,
     const guchar* src, int srcChannels, int srcStride,
@@ -587,7 +585,6 @@ static void CopyImageData(
         }
     }
 }
-#endif
 
 #if wxUSE_IMAGE
 #ifdef __WXGTK3__
@@ -1365,6 +1362,26 @@ void wxBitmap::Draw(cairo_t* cr, int x, int y, bool useMask, const wxColour* fg,
     else
         cairo_paint(cr);
 }
+#else
+GdkPixbuf* wxBitmap::GetPixbufNoMask() const
+{
+    wxCHECK_MSG(IsOk(), NULL, "invalid bitmap");
+
+    wxBitmapRefData* bmpData = M_BMPDATA;
+    GdkPixbuf* pixbuf = bmpData->m_pixbuf;
+    if (pixbuf)
+        return pixbuf;
+
+    const int w = bmpData->m_width;
+    const int h = bmpData->m_height;
+
+    pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, bmpData->m_alphaRequested, 8, w, h);
+    if ( bmpData->m_pixmap )
+        PixmapToPixbuf(bmpData->m_pixmap, pixbuf, w, h);
+
+    bmpData->m_pixbuf = pixbuf;
+    return pixbuf;
+}
 #endif
 
 GdkPixbuf *wxBitmap::GetPixbuf() const
@@ -1405,21 +1422,31 @@ GdkPixbuf *wxBitmap::GetPixbuf() const
 
     return bmpData->m_pixbufMask;
 #else
-    if (bmpData->m_pixbuf)
+    if ( bmpData->m_pixbufMask )
-        return bmpData->m_pixbuf;
+        return bmpData->m_pixbufMask;
 
     const int w = bmpData->m_width;
     const int h = bmpData->m_height;
+    if ( !bmpData->m_pixbuf )
+        GetPixbufNoMask();
+
     GdkPixmap* mask = NULL;
     if (bmpData->m_mask)
         mask = *bmpData->m_mask;
-    const bool useAlpha = bmpData->m_alphaRequested || mask;
+
-    bmpData->m_pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, useAlpha, 8, w, h);
+    if ( !mask )
-    if (bmpData->m_pixmap)
+        return bmpData->m_pixbuf;
-        PixmapToPixbuf(bmpData->m_pixmap, bmpData->m_pixbuf, w, h);
+
-    if (mask)
+    bmpData->m_pixbufMask = gdk_pixbuf_new(GDK_COLORSPACE_RGB, true, 8, w, h);
-        MaskToAlpha(mask, bmpData->m_pixbuf, w, h);
+    guchar* dst = gdk_pixbuf_get_pixels(bmpData->m_pixbufMask);
-    return bmpData->m_pixbuf;
+    guchar* src = gdk_pixbuf_get_pixels(bmpData->m_pixbuf);
+    const int dstStride = gdk_pixbuf_get_rowstride(bmpData->m_pixbufMask);
+    const int srcStride = gdk_pixbuf_get_rowstride(bmpData->m_pixbuf);
+    CopyImageData(dst, 4, dstStride,
+                  src, gdk_pixbuf_get_n_channels(bmpData->m_pixbuf), srcStride,
+                  w, h);
+    MaskToAlpha(mask, bmpData->m_pixbufMask, w, h);
+    return bmpData->m_pixbufMask;
 #endif
 }
 
@@ -1471,11 +1498,17 @@ void *wxBitmap::GetRawData(wxPixelDataBase& data, int bpp)
         }
     }
 #else
-    GdkPixbuf *pixbuf = GetPixbuf();
+    GdkPixbuf *pixbuf = GetPixbufNoMask();
 
     // Pixmap will get out of date when our pixbuf is accessed directly, so
     // ensure we don't keep the old data in it.
     PurgeOtherRepresentations(Pixbuf);
+    // Pixbuf with masked data will get out of date too
+    if ( M_BMPDATA->m_pixbufMask )
+    {
+        g_object_unref(M_BMPDATA->m_pixbufMask);
+        M_BMPDATA->m_pixbufMask = NULL;
+    }
 
     const bool hasAlpha = HasAlpha();