Fix #2718: Sphinx crashes if the document file is not readable

CHANGES

@@ -41,6 +41,7 @@ Bugs fixed
 * #2666: C++, properly look up nested names involving constructors.
 * #2579: Could not refer a label including both spaces and colons via
   `sphinx.ext.intersphinx`
+* #2718: Sphinx crashes if the document file is not readable
 
 
 Release 1.4.4 (released Jun 12, 2016)

sphinx/application.py

@@ -239,8 +239,8 @@ class Sphinx(object):
 
     def _init_env(self, freshenv):
         if freshenv:
-            self.env = BuildEnvironment(self.srcdir, self.doctreedir,
-                                        self.config)
+            self.env = BuildEnvironment(self.srcdir, self.doctreedir, self.config)
+            self.env.set_warnfunc(self.warn)
             self.env.find_files(self.config)
             for domain in self.domains.keys():
                 self.env.domains[domain] = self.domains[domain](self.env)
@@ -249,6 +249,7 @@ class Sphinx(object):
                 self.info(bold('loading pickled environment... '), nonl=True)
                 self.env = BuildEnvironment.frompickle(
                     self.srcdir, self.config, path.join(self.doctreedir, ENV_PICKLE_FILENAME))
+                self.env.set_warnfunc(self.warn)
                 self.env.domains = {}
                 for domain in self.domains.keys():
                     # this can raise if the data version doesn't fit
@@ -261,8 +262,6 @@ class Sphinx(object):
                     self.info('failed: %s' % err)
                 return self._init_env(freshenv=True)
 
-        self.env.set_warnfunc(self.warn)
-
     def _init_builder(self, buildername):
         if buildername is None:
             print('No builder selected, using default: html', file=self._status)

sphinx/environment.py

@@ -409,8 +409,13 @@ class BuildEnvironment:
             config.html_extra_path +
             ['**/_sources', '.#*', '**/.#*', '*.lproj/**']
         )
-        self.found_docs = set(get_matching_docs(
-            self.srcdir, config.source_suffix, exclude_matchers=matchers))
+        self.found_docs = set()
+        for docname in get_matching_docs(self.srcdir, config.source_suffix,
+                                         exclude_matchers=matchers):
+            if os.access(self.doc2path(docname), os.R_OK):
+                self.found_docs.add(docname)
+            else:
+                self.warn(docname, "document not readable. Ignored.")
 
         # add catalog mo file dependency
         for docname in self.found_docs: