Merge pull request #16537 from anntzer/delaydistillercheck

QuLogic · web-flow · commit a1cd0240c9f2 · 2020-03-10T02:43:39.000-04:00
Delay checking for existence of postscript distillers.
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -981,9 +981,11 @@ def print_figure_impl(fh):
                 with open(tmpfile, 'w', encoding='latin-1') as fh:
                     print_figure_impl(fh)
                 if mpl.rcParams['ps.usedistiller'] == 'ghostscript':
-                    gs_distill(tmpfile, is_eps, ptype=papertype, bbox=bbox)
+                    _try_distill(gs_distill,
+                                 tmpfile, is_eps, ptype=papertype, bbox=bbox)
                 elif mpl.rcParams['ps.usedistiller'] == 'xpdf':
-                    xpdf_distill(tmpfile, is_eps, ptype=papertype, bbox=bbox)
+                    _try_distill(xpdf_distill,
+                                 tmpfile, is_eps, ptype=papertype, bbox=bbox)
                 _move_path_to_path_or_stream(tmpfile, outfile)
 
         else:
@@ -1141,10 +1143,12 @@ def write(self, *args, **kwargs):
 
             if (mpl.rcParams['ps.usedistiller'] == 'ghostscript'
                     or mpl.rcParams['text.usetex']):
-                gs_distill(tmpfile, is_eps, ptype=papertype, bbox=bbox,
-                           rotated=psfrag_rotated)
+                _try_distill(gs_distill,
+                             tmpfile, is_eps, ptype=papertype, bbox=bbox,
+                             rotated=psfrag_rotated)
             elif mpl.rcParams['ps.usedistiller'] == 'xpdf':
-                xpdf_distill(tmpfile, is_eps, ptype=papertype, bbox=bbox,
+                _try_distill(xpdf_distill,
+                             tmpfile, is_eps, ptype=papertype, bbox=bbox,
                              rotated=psfrag_rotated)
 
             _move_path_to_path_or_stream(tmpfile, outfile)
@@ -1198,6 +1202,13 @@ def convert_psfrags(tmpfile, psfrags, font_preamble, custom_preamble,
     return psfrag_rotated
 
 
+def _try_distill(func, *args, **kwargs):
+    try:
+        func(*args, **kwargs)
+    except mpl.ExecutableNotFoundError as exc:
+        _log.warning("%s.  Distillation step skipped.", exc)
+
+
 def gs_distill(tmpfile, eps=False, ptype='letter', bbox=None, rotated=False):
     """
     Use ghostscript's pswrite or epswrite device to distill a file.
@@ -1239,6 +1250,9 @@ def xpdf_distill(tmpfile, eps=False, ptype='letter', bbox=None, rotated=False):
     operators. This distiller is preferred, generating high-level postscript
     output that treats text as text.
     """
+    mpl._get_executable_info("gs")  # Effectively checks for ps2pdf.
+    mpl._get_executable_info("pdftops")
+
     pdffile = tmpfile + '.pdf'
     psfile = tmpfile + '.ps'
 
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -24,7 +24,6 @@
 
 import numpy as np
 
-import matplotlib as mpl
 from matplotlib import animation, cbook
 from matplotlib.cbook import ls_mapper
 from matplotlib.fontconfig_pattern import parse_fontconfig_pattern
@@ -524,24 +523,8 @@ def validate_ps_distiller(s):
         s = s.lower()
     if s in ('none', None, 'false', False):
         return None
-    elif s in ('ghostscript', 'xpdf'):
-        try:
-            mpl._get_executable_info("gs")
-        except mpl.ExecutableNotFoundError:
-            _log.warning("Setting rcParams['ps.usedistiller'] requires "
-                         "ghostscript.")
-            return None
-        if s == "xpdf":
-            try:
-                mpl._get_executable_info("pdftops")
-            except mpl.ExecutableNotFoundError:
-                _log.warning("Setting rcParams['ps.usedistiller'] to 'xpdf' "
-                             "requires xpdf.")
-                return None
-        return s
     else:
-        raise ValueError('matplotlibrc ps.usedistiller must either be none, '
-                         'ghostscript or xpdf')
+        return ValidateInStrings('ps.usedistiller', ['ghostscript', 'xpdf'])(s)
 
 
 # A validator dedicated to the named line styles, based on the items in
