pgf: Add clipping to text outputs

Fixes matplotlib#11375

Author: QuLogic

lib/matplotlib/backends/backend_pgf.py

@@ -657,6 +657,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         s = _escape_and_apply_props(s, prop)
 
         _writeln(self.fh, r"\begin{pgfscope}")
+        self._print_pgf_clip(gc)
 
         alpha = gc.get_alpha()
         if alpha != 1.0:

lib/matplotlib/tests/test_backend_pgf.py

@@ -67,6 +67,8 @@ def create_figure():
              ha='right', fontsize=20)
     plt.ylabel('sans-serif, blue, $\\frac{\\sqrt{x}}{y^2}$..',
                family='sans-serif', color='blue')
+    plt.text(1, 1, 'should be clipped as default clip_box is Axes bbox',
+             fontsize=20, clip_on=True)
 
     plt.xlim(0, 1)
     plt.ylim(0, 1)