filter: set environment variable PYTHONIOENCODING to utf-8

This allows different versions of Python to be used rather than
forcing version specific encoding in each script.

Signed-off-by: Roy Marples <roy@marples.name>
Signed-off-by: John Keeping <john@keeping.me.uk>

filter.c

@@ -55,6 +55,8 @@ static int open_exec_filter(struct cgit_filter *base, va_list ap)
 		close(filter->pipe_fh[1]);
 		chk_non_negative(dup2(filter->pipe_fh[0], STDIN_FILENO),
 			"Unable to use pipe as STDIN");
+		/* Always input/output utf-8 for a Python filter. */
+		setenv("PYTHONIOENCODING", "utf-8", 1);
 		execvp(filter->cmd, filter->argv);
 		die_errno("Unable to exec subprocess %s", filter->cmd);
 	}

filters/email-gravatar.py

@@ -30,9 +30,6 @@ if email[-1] == '>':
 
 page = sys.argv[2]
 
-sys.stdin = codecs.getreader("utf-8")(sys.stdin.detach())
-sys.stdout = codecs.getwriter("utf-8")(sys.stdout.detach())
-
 md5 = hashlib.md5(email.encode()).hexdigest()
 text = sys.stdin.read().strip()
 

filters/syntax-highlighting.py

@@ -29,9 +29,6 @@ from pygments.lexers import guess_lexer
 from pygments.lexers import guess_lexer_for_filename
 from pygments.formatters import HtmlFormatter
 
-
-sys.stdin = io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8', errors='replace')
-sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
 data = sys.stdin.read()
 filename = sys.argv[1]
 formatter = HtmlFormatter(style='pastie')
@@ -52,4 +49,4 @@ except TypeError:
 sys.stdout.write('<style>')
 sys.stdout.write(formatter.get_style_defs('.highlight'))
 sys.stdout.write('</style>')
-sys.stdout.write(highlight(data, lexer, formatter, outfile=None))
+highlight(data, lexer, formatter, outfile=sys.stdout)