diff --git a/dialogs/imagelib/kpDocumentMetaInfoDialog.cpp b/dialogs/imagelib/kpDocumentMetaInfoDialog.cpp
--- a/dialogs/imagelib/kpDocumentMetaInfoDialog.cpp
+++ b/dialogs/imagelib/kpDocumentMetaInfoDialog.cpp
@@ -688,23 +688,6 @@
             fieldsAppendEmptyRow ();
         }
     }
-// Deletes a row if it is emptied of text.
-#if 0
-    // At any normal row?
-    else
-    {   // Emptied all the text?
-        if (key.isEmpty () && value.isEmpty ())
-        {
-            // This crashes when the user tabs away after the text is deleted.
-            // We could use a single shot but that's asking for trouble depending
-            // on what happens between us and the single shot.
-            //
-            // In any case, disabling this makes us more consistent with
-            // "Add Row" which allows us to add empty rows.
-            //fieldsDeleteRow (r);
-        }
-    }
-#endif
 }
 
 //---------------------------------------------------------------------
diff --git a/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp b/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp
--- a/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp
+++ b/dialogs/imagelib/transforms/kpTransformPreviewDialog.cpp
@@ -333,12 +333,6 @@
             scaleDimension (m_oldHeight,
                             keepsAspectScale,
                             1, m_previewPixmapLabel->height ()));
-    #if 0
-        m_shrunkenDocumentPixmap = kpPixmapFX::scale (
-            m_actOnSelection ? doc->getSelectedPixmap () : *doc->pixmap (),
-            m_previewPixmapLabel->width (),
-            m_previewPixmapLabel->height ());
-    #endif
 
         m_previewPixmapLabelSizeWhenUpdatedPixmap = m_previewPixmapLabel->size ();
     }
diff --git a/imagelib/effects/kpEffectBalance.cpp b/imagelib/effects/kpEffectBalance.cpp
--- a/imagelib/effects/kpEffectBalance.cpp
+++ b/imagelib/effects/kpEffectBalance.cpp
@@ -171,13 +171,6 @@
                            transformGreen [green],
                            transformBlue [blue],
                            alpha));
-
-            #if 0
-                qimage.setPixel (x, y,
-                    brightnessContrastGammaForRGB (qimage.pixel (x, y),
-                        channels,
-                        brightness, contrast, gamma));
-            #endif
             }
         }
     }
@@ -197,13 +190,6 @@
                        transformGreen [green],
                        transformBlue [blue],
                        alpha));
-
-        #if 0
-            qimage.setColor (i,
-                brightnessContrastGammaForRGB (qimage.color (i),
-                    channels,
-                    brightness, contrast, gamma));
-        #endif
         }
 
     }
diff --git a/imagelib/effects/kpEffectBlurSharpen.cpp b/imagelib/effects/kpEffectBlurSharpen.cpp
--- a/imagelib/effects/kpEffectBlurSharpen.cpp
+++ b/imagelib/effects/kpEffectBlurSharpen.cpp
@@ -123,25 +123,6 @@
         (RepeatMax - RepeatMin) /
         (kpEffectBlurSharpen::MaxStrength - 1));
 
-// I guess these values are more proper as they use an auto-calculated
-// radius but they cause sharpen() to be too slow.
-#if 0
-    const double radius = 0/*auto-calculate*/;
-
-    const double SigmaMin = 0.6;
-    const double SigmaMax = 1.0;
-    const double sigma = SigmaMin +
-        (strength - 1) *
-        (SigmaMax - SigmaMin) /
-        (kpEffectBlurSharpen::MaxStrength - 1);
-
-    const double RepeatMin = 1;
-    const double RepeatMax = 3;
-    const double repeat = qRound (RepeatMin +
-        (strength - 1) *
-        (RepeatMax - RepeatMin) /
-        (kpEffectBlurSharpen::MaxStrength - 1));
-#endif
 
 #if DEBUG_KP_EFFECT_BLUR_SHARPEN
     qCDebug(kpLogImagelib) << "kpEffectBlurSharpen.cpp:SharpenQImage(strength=" << strength << ")"
diff --git a/imagelib/effects/kpEffectEmboss.cpp b/imagelib/effects/kpEffectEmboss.cpp
--- a/imagelib/effects/kpEffectEmboss.cpp
+++ b/imagelib/effects/kpEffectEmboss.cpp
@@ -51,15 +51,6 @@
 
     const double radius = 0;
 
-#if 0
-    const double SigmaMin = 1;
-    const double SigmaMax = 1.2;
-
-    return SigmaMin +
-        (kpEffectEmboss::MaxStrength - strength) *
-        (SigmaMax - SigmaMin) /
-        (kpEffectEmboss::MaxStrength - 1);
-#endif
     const double sigma = 1;
 
     const int repeat = 1;
diff --git a/imagelib/effects/kpEffectInvert.cpp b/imagelib/effects/kpEffectInvert.cpp
--- a/imagelib/effects/kpEffectInvert.cpp
+++ b/imagelib/effects/kpEffectInvert.cpp
@@ -54,10 +54,6 @@
 
     if (destImagePtr->depth () > 8)
     {
-    #if 0
-        // SYNC: TODO: Qt BUG - invertAlpha argument is inverted!!!
-        destImagePtr->invertPixels (true/*no invert alpha (Qt 3.2)*/);
-    #else
         // Above version works for Qt 3.2 at least.
         // But this version will always work (slower, though) and supports
         // inverting particular channels.
@@ -68,7 +64,6 @@
                 destImagePtr->setPixel (x, y, destImagePtr->pixel (x, y) ^ mask);
             }
         }
-    #endif
     }
     else
     {
diff --git a/imagelib/kpPainter.cpp b/imagelib/kpPainter.cpp
--- a/imagelib/kpPainter.cpp
+++ b/imagelib/kpPainter.cpp
@@ -83,11 +83,6 @@
 #define SHOULD_DRAW()  (probabilityTimes1000 == 1000/*avoid ::RandomNumberFrom0to999() call*/ ||  \
                         ::RandomNumberFrom0to999 () < probabilityTimes1000)
 
-#if 0
-    qCDebug(kpLogImagelib) << "prob=" << probability
-               << " *1000=" << probabilityTimes1000;
-#endif
-
 
     // Derived from the zSprite2 Graphics Engine.
     // "MODIFIED" comment shows deviation from zSprite2 and Bresenham's line
diff --git a/imagelib/transforms/kpTransformCrop_ImageSelection.cpp b/imagelib/transforms/kpTransformCrop_ImageSelection.cpp
--- a/imagelib/transforms/kpTransformCrop_ImageSelection.cpp
+++ b/imagelib/transforms/kpTransformCrop_ImageSelection.cpp
@@ -169,12 +169,6 @@
         #endif
         }
 
-#if 0
-        kpPixmapFX::paintMaskTransparentWithBrush (&newDocImage,
-            QPoint (0, 0),
-            m_fromSelectionPtr->shapeBitmap ());
-#endif
-
         kpPixmapFX::paintPixmapAt (&newDocImage,
             QPoint (0, 0),
             setTransparentImage);
diff --git a/mainWindow/kpMainWindow.cpp b/mainWindow/kpMainWindow.cpp
--- a/mainWindow/kpMainWindow.cpp
+++ b/mainWindow/kpMainWindow.cpp
@@ -399,56 +399,6 @@
         #endif
             configGroup.writeEntry (kpSessionSettingNotFromUrlDocumentSize, docSize);
         }
-
-
-        // Local session save i.e. queryClose() was not called beforehand
-        // (see QApplication::saveState())?
-    #if 0
-        if (d->document->isModified ())
-        {
-            // TODO: Implement by saving the current image to a persistent file.
-            //       We do this instead of saving/mutating the backing image file
-            //       as no one expects a file save on a session save without a
-            //       "do you want to save" dialog first.
-            //
-            //       I don't think any KDE application implements local session saving.
-            //
-            //       --- The below code does not compile but shows you want to do ---
-
-            // Create unique name for the document in this main window.
-            const QUrl tempURL = homeDir +
-                "kolourpaint session " + sessionID +
-                mainWindowPtrToString + ".png";
-            // TODO: Use lossless PNG saving options.
-            kpDocumentSaveOptions pngSaveOptions;
-
-            if (kpDocument::savePixmapToFile (d->document->pixmapWithSelection (),
-                    tempURL,
-                    pngSaveOptions, *d->document->metaInfo (),
-                    false/*no overwrite prompt*/,
-                    false/*no lossy prompt*/,
-                    this))
-            {
-                // readProperties() will still open kpSessionSettingDocumentUrl
-                // (as that's the expected URL) and will then add commands to:
-                //
-                // 1. Resize the document to the size of image at
-                //    kpSessionSettingDocumentUnsavedContentsUrl, if the sizes
-                //    differ.
-                // 2. Paste the kpSessionSettingDocumentUnsavedContentsUrl image
-                //    (setting the main window's selection mode to opaque beforehand).
-                //
-                // It will then delete the file at
-                // kpSessionSettingDocumentUnsavedContentsUrl.
-                configGroup.writeEntry (kpSessionSettingDocumentUnsavedContentsUrl,
-                    tempURL.url ());
-            }
-            else
-            {
-                // Not much we can do - we aren't allowed to throw up a dialog.
-            }
-        }
-    #endif
     }
 }
 
@@ -768,30 +718,6 @@
         enableToolsDocumentActions (true);
 
         enableDocumentActions (true);
-
-    // TODO: The thumbnail auto zoom doesn't work because it thinks its
-    //       width == 1 when !this->isShown().  So for consistency,
-    //       never create the thumbnail.
-    #if 0
-        if (d->configThumbnailShown)
-        {
-            if (isShown ())
-            {
-            #if DEBUG_KP_MAIN_WINDOW
-                qCDebug(kpLogMainWindow) << "\tcreating thumbnail immediately";
-            #endif
-                slotCreateThumbnail ();
-            }
-            // this' geometry is weird ATM
-            else
-            {
-            #if DEBUG_KP_MAIN_WINDOW
-                qCDebug(kpLogMainWindow) << "\tcreating thumbnail LATER";
-            #endif
-                QTimer::singleShot (0, this, SLOT (slotCreateThumbnail()));
-            }
-        }
-    #endif
     }
 
 #if DEBUG_KP_MAIN_WINDOW
diff --git a/mainWindow/kpMainWindow_View_Zoom.cpp b/mainWindow/kpMainWindow_View_Zoom.cpp
--- a/mainWindow/kpMainWindow_View_Zoom.cpp
+++ b/mainWindow/kpMainWindow_View_Zoom.cpp
@@ -184,24 +184,6 @@
 
     zoomLevel = qBound (kpView::MinZoomLevel, zoomLevel, kpView::MaxZoomLevel);
 
-// mute point since the thumbnail suffers from this too
-#if 0
-    else if (d->mainView && d->mainView->zoomLevelX () % 100 == 0 && zoomLevel % 100)
-    {
-        if (KMessageBox::warningContinueCancel (this,
-            i18n ("Setting the zoom level to a value that is not a multiple of 100% "
-                  "results in imprecise editing and redraw glitches.\n"
-                  "Do you really want to set to zoom level to %1%?",
-                  zoomLevel),
-            QString()/*caption*/,
-            i18n ("Set Zoom Level to %1%", zoomLevel),
-            "DoNotAskAgain_ZoomLevelNotMultipleOf100") != KMessageBox::Continue)
-        {
-            zoomLevel = d->mainView->zoomLevelX ();
-        }
-    }
-#endif
-
     int index = 0;
     QList <int>::Iterator it = d->zoomList.begin ();
 
diff --git a/pixmapfx/kpPixmapFX_Transforms.cpp b/pixmapfx/kpPixmapFX_Transforms.cpp
--- a/pixmapfx/kpPixmapFX_Transforms.cpp
+++ b/pixmapfx/kpPixmapFX_Transforms.cpp
@@ -150,18 +150,6 @@
         qCDebug(kpLogPixmapfx) << "(w-1,h-1) ->" << matrix.map (QPoint (w - 1, h - 1));
     }
 
-#if 0
-    QMatrix trueMatrix = QPixmap::trueMatrix (matrix, w, h);
-    qCDebug(kpLogPixmapfx) << matrixName << "trueMatrix=" << trueMatrix;
-    if (w > 0 && h > 0)
-    {
-        qCDebug(kpLogPixmapfx) << "(0,0) ->" << trueMatrix.map (QPoint (0, 0));
-        qCDebug(kpLogPixmapfx) << "(w-1,0) ->" << trueMatrix.map (QPoint (w - 1, 0));
-        qCDebug(kpLogPixmapfx) << "(0,h-1) ->" << trueMatrix.map (QPoint (0, h - 1));
-        qCDebug(kpLogPixmapfx) << "(w-1,h-1) ->" << trueMatrix.map (QPoint (w - 1, h - 1));
-    }
-#endif
-
 #else
 
     Q_UNUSED (matrixName);
diff --git a/views/manager/kpViewManager_TextCursor.cpp b/views/manager/kpViewManager_TextCursor.cpp
--- a/views/manager/kpViewManager_TextCursor.cpp
+++ b/views/manager/kpViewManager_TextCursor.cpp
@@ -160,15 +160,6 @@
     }
     restoreQueueUpdates ();
     restoreFastUpdates ();
-
-#if 0 // TODO port to Qt5?
-    if (d->viewUnderCursor) {
-        QInputContext *inputContext = d->viewUnderCursor->inputContext ();
-        if (inputContext) {
-            inputContext->update ();
-        }
-    }
-#endif
 }
 
 
diff --git a/widgets/imagelib/effects/kpEffectEmbossWidget.cpp b/widgets/imagelib/effects/kpEffectEmbossWidget.cpp
--- a/widgets/imagelib/effects/kpEffectEmbossWidget.cpp
+++ b/widgets/imagelib/effects/kpEffectEmbossWidget.cpp
@@ -49,27 +49,6 @@
     lay->setMargin (0);
 
 
-#if 0
-    QLabel *amountLabel = new QLabel (i18n ("&Amount:"), this);
-    m_amountInput = new kpIntNumInput (this);
-    m_amountInput->setRange (kpEffectEmboss::MinStrength,
-        kpEffectEmboss::MaxStrength, 1/*step*/, true/*slider*/);
-    m_amountInput->setSpecialValueText (i18n ("None"));
-
-
-    amountLabel->setBuddy (m_amountInput);
-
-
-    lay->addWidget (amountLabel, 0, 0);
-    lay->addWidget (m_amountInput, 0, 1);
-
-    lay->setColumnStretch (1, 1);
-
-
-    connect (m_amountInput, &kpIntNumInput::valueChanged,
-             this, &kpEffectEmbossWidget::settingsChanged);
-#endif
-
     m_enableCheckBox = new QCheckBox (i18n ("E&nable"), this);