[PATCH 5/3] docs: sphinx/kfigure.py: Delegate inkscape msgs to kernellog

[Akira Yokosawa <akiyks@gmail.com>]

Instead of redirecting to /dev/null, capture inkscape messages and
output them via kernelloc.verbose or kerneldoc.warn depending on the
exit code.

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
---
Hi Mauro,

On second thought, I took the path of delegating inkscape warnings
to kernellog.

Now you can see those warning messages by "SPHINXOPTS=-v".

Does this approach sound reasonable to you?

        Thanks, Akira
--
 Documentation/sphinx/kfigure.py | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/Documentation/sphinx/kfigure.py b/Documentation/sphinx/kfigure.py
index dbe75ee8ae61..a275ee0fec02 100644
--- a/Documentation/sphinx/kfigure.py
+++ b/Documentation/sphinx/kfigure.py
@@ -126,9 +126,6 @@ rsvg_convert_cmd = None
 inkscape_cmd = None
 # Inkscape prior to 1.0 uses different command options
 inkscape_ver_one = False
-# Show warning from inkscape(1), enabled by setting env var
-# SPHINX_SHOW_INKSCAPE_WARN
-inkscape_show_warn = False
 
 
 def setup(app):
@@ -178,7 +175,7 @@ def setupTools(app):
     This function is called once, when the builder is initiated.
     """
     global dot_cmd, dot_Tpdf, convert_cmd, rsvg_convert_cmd   # pylint: disable=W0603
-    global inkscape_cmd, inkscape_ver_one, inkscape_show_warn  # pylint: disable=W0603
+    global inkscape_cmd, inkscape_ver_one  # pylint: disable=W0603
     kernellog.verbose(app, "kfigure: check installed tools ...")
 
     dot_cmd = which('dot')
@@ -211,12 +208,6 @@ def setupTools(app):
         rsvg_convert_cmd = None
         dot_Tpdf = False
 
-        try:
-            if os.environ['SPHINX_SHOW_INKSCAPE_WARN']:
-                inkscape_show_warn = True
-        except KeyError:
-            pass
-
     else:
         if convert_cmd:
             kernellog.verbose(app, "use convert(1) from: " + convert_cmd)
@@ -384,14 +375,21 @@ def svg2pdf(app, svg_fname, pdf_fname):
         else:
             cmd = [inkscape_cmd, '-z', '--export-pdf=%s' % pdf_fname, svg_fname]
 
-    # use stdout and stderr from parent
-    if inkscape_show_warn:
-        exit_code = subprocess.call(cmd)
-    else:
-        exit_code = subprocess.call(cmd, stderr=subprocess.DEVNULL)
+    try:
+        warning_msg = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
+        exit_code = 0
+    except subprocess.CalledProcessError as err:
+        warning_msg = err.output
+        exit_code = 1
+        pass
 
     if exit_code != 0:
         kernellog.warn(app, "Error #%d when calling: %s" % (exit_code, " ".join(cmd)))
+        kernellog.warn(app, "Warning msg from inkscape: %s" % str(warning_msg, 'utf-8'))
+    if warning_msg:
+        kernellog.verbose(app, "Warning msg from inkscape (likely harmless):\n%s"
+                          % str(warning_msg, 'utf-8'))
+
     return bool(exit_code == 0)
 
 def svg2pdf_by_rsvg(app, svg_fname, pdf_fname):
-- 
2.17.1