matplotlib · jklymak · May 7, 2018 · May 7, 2018
diff --git a/lib/matplotlib/_constrained_layout.py b/lib/matplotlib/_constrained_layout.py
@@ -244,7 +244,7 @@ def do_constrained_layout(fig, renderer, h_pad, w_pad,
                 ax._poslayoutbox.constrain_left_margin(0, strength='weak')
 
     # do layout for suptitle.
-    if fig._suptitle is not None:
+    if fig._suptitle is not None and fig._suptitle._layoutbox is not None:
         sup = fig._suptitle
         bbox = invTransFig(sup.get_window_extent(renderer=renderer))
         height = bbox.y1 - bbox.y0

diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
@@ -718,6 +718,8 @@ def suptitle(self, t, **kwargs):
 
           fig.suptitle('this is the figure title', fontsize=12)
         """
+        manual_position = ('x' in kwargs or 'y' in kwargs)
+
         x = kwargs.pop('x', 0.5)
         y = kwargs.pop('y', 0.98)
 
@@ -740,19 +742,22 @@ def suptitle(self, t, **kwargs):
             sup.remove()
         else:
             self._suptitle = sup
-        if self._layoutbox is not None:
-            # assign a layout box to the suptitle...
-            figlb = self._layoutbox
-            self._suptitle._layoutbox = layoutbox.LayoutBox(
-                                            parent=figlb,
-                                            name=figlb.name+'.suptitle')
-            for child in figlb.children:
-                if not (child == self._suptitle._layoutbox):
-                    w_pad, h_pad, wspace, hspace =  \
-                            self.get_constrained_layout_pads(
-                                    relative=True)
-                    layoutbox.vstack([self._suptitle._layoutbox, child],
-                                     padding=h_pad*2., strength='required')
+            self._suptitle._layoutbox = None
+            if self._layoutbox is not None and not manual_position:
+                w_pad, h_pad, wspace, hspace =  \
+                        self.get_constrained_layout_pads(relative=True)
+                figlb = self._layoutbox
+                self._suptitle._layoutbox = layoutbox.LayoutBox(
+                        parent=figlb, artist=self._suptitle,
+                        name=figlb.name+'.suptitle')
+                # stack the suptitle on top of all the children.
+                # Some day this should be on top of all the children in the
+                # gridspec only.
+                for child in figlb.children:
+                    if child is not self._suptitle._layoutbox:
+                        layoutbox.vstack([self._suptitle._layoutbox,
+                                          child],
+                                         padding=h_pad*2., strength='required')
         self.stale = True
         return self._suptitle
 

diff --git a/lib/matplotlib/tests/test_constrainedlayout.py b/lib/matplotlib/tests/test_constrainedlayout.py
@@ -388,3 +388,43 @@ def test_constrained_layout20():
     ax = fig.add_axes([0, 0, 1, 1])
     mesh = ax.pcolormesh(gx, gx, img)
     fig.colorbar(mesh)
+
+
+def test_constrained_layout21():
+    '#11035: repeated calls to suptitle should not alter the layout'
+    fig, ax = plt.subplots(constrained_layout=True)
+
+    fig.suptitle("Suptitle0")
+    fig.canvas.draw()
+    extents0 = np.copy(ax.get_position().extents)
+
+    fig.suptitle("Suptitle1")
+    fig.canvas.draw()
+    extents1 = np.copy(ax.get_position().extents)
+
+    np.testing.assert_allclose(extents0, extents1)
+
+
+def test_constrained_layout22():
+    '#11035: suptitle should not be include in CL if manually positioned'
+    fig, ax = plt.subplots(constrained_layout=True)
+
+    fig.canvas.draw()
+    extents0 = np.copy(ax.get_position().extents)
+
+    fig.suptitle("Suptitle", y=0.5)
+    fig.canvas.draw()
+    extents1 = np.copy(ax.get_position().extents)
+
+    np.testing.assert_allclose(extents0, extents1)
+
+
+def test_constrained_layout23():
+    '''
+    Comment in #11035: suptitle used to cause an exception when
+    reusing a figure w/ CL with ``clear=True``.
+    '''
+
+    for i in range(2):
+        fig, ax = plt.subplots(num="123", constrained_layout=True, clear=True)
+        fig.suptitle("Suptitle{}".format(i))