docs: kdoc: handle the obsolescensce of docutils.ErrorString()

commit 00d95fcc4d upstream.

The ErrorString() and SafeString() docutils functions were helpers meant to
ease the handling of encodings during the Python 3 transition.  There is no
real need for them after Python 3.6, and docutils 0.22 removes them,
breaking the docs build

Handle this by just injecting our own one-liner version of ErrorString(),
and removing the sole SafeString() call entirely.

Reported-by: Zhixu Liu <zhixu.liu@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <87ldmnv2pi.fsf@trenco.lwn.net>
[ Salvatore Bonaccorso: Backport to v6.17.y for context changes in
  Documentation/sphinx/kernel_include.py with major refactorings for the v6.18
  development cycle ]
Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/sphinx/kernel_feat.py

@@ -40,9 +40,11 @@ import sys
 from docutils import nodes, statemachine
 from docutils.statemachine import ViewList
 from docutils.parsers.rst import directives, Directive
-from docutils.utils.error_reporting import ErrorString
 from sphinx.util.docutils import switch_source_input
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 __version__  = '1.0'
 
 def setup(app):

Documentation/sphinx/kernel_include.py

@@ -35,13 +35,15 @@
 import os.path
 
 from docutils import io, nodes, statemachine
-from docutils.utils.error_reporting import SafeString, ErrorString
 from docutils.parsers.rst import directives
 from docutils.parsers.rst.directives.body import CodeBlock, NumberLines
 from docutils.parsers.rst.directives.misc import Include
 
 __version__  = '1.0'
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 # ==============================================================================
 def setup(app):
 # ==============================================================================
@@ -112,7 +114,7 @@ class KernelInclude(Include):
             raise self.severe('Problems with "%s" directive path:\n'
                               'Cannot encode input file path "%s" '
                               '(wrong locale?).' %
-                              (self.name, SafeString(path)))
+                              (self.name, path))
         except IOError as error:
             raise self.severe('Problems with "%s" directive path:\n%s.' %
                       (self.name, ErrorString(error)))

Documentation/sphinx/maintainers_include.py

@@ -22,10 +22,12 @@ import re
 import os.path
 
 from docutils import statemachine
-from docutils.utils.error_reporting import ErrorString
 from docutils.parsers.rst import Directive
 from docutils.parsers.rst.directives.misc import Include
 
+def ErrorString(exc):  # Shamelessly stolen from docutils
+    return f'{exc.__class__.__name}: {exc}'
+
 __version__  = '1.0'
 
 def setup(app):