procutil: make stream detection in make_line_buffered more correct and strict In make_line_buffered(), we don’t want to wrap the stream if we know that lines get flushed to the underlying raw stream already. Previously, the heuristic was too optimistic. It assumed that any stream which is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there are buffered streams that aren’t instances of io.BufferedIOBase, like Mercurial’s own winstdout. The new logic is different in two ways: First, only for the check, if unwraps any combination of WriteAllWrapper and winstdout. Second, it skips wrapping the stream only if it is an instance of io.RawIOBase (or already wrapped). If it is an instance of io.BufferedIOBase, it gets wrapped. In any other case, the function raises an exception. This ensures that, if an unknown stream is passed or we add another wrapper in the future, we don’t wrap the stream if it’s already line buffered or not wrap the stream if it’s not line buffered. In fact, this was already helpful during development of this change. Without it, I possibly would have forgot that WriteAllWrapper needs to be ignored for the check, leading to unnecessary wrapping if stdout is unbuffered. The alternative would have been to always wrap unknown streams. However, I don’t think that anyone would benefit from being less strict. We can expect streams from the standard library to be subclassing either io.RawIOBase or io.BufferedIOBase, so running Mercurial in the standard way should not regress by this change. Py2exe might replace sys.stdout and sys.stderr, but that currently breaks Mercurial anyway and also these streams don’t claim to be interactive, so this function is not called for them.

     1

DOCUMENT_ROOT="/var/www/hg"; export DOCUMENT_ROOT

     2

GATEWAY_INTERFACE="CGI/1.1"; export GATEWAY_INTERFACE

     3

HTTP_ACCEPT="text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"; export HTTP_ACCEPT

     4

HTTP_ACCEPT_CHARSET="ISO-8859-1,utf-8;q=0.7,*;q=0.7"; export HTTP_ACCEPT_CHARSET

     5

HTTP_ACCEPT_ENCODING="gzip,deflate"; export HTTP_ACCEPT_ENCODING

     6

HTTP_ACCEPT_LANGUAGE="en-us,en;q=0.5"; export HTTP_ACCEPT_LANGUAGE

     7

HTTP_CACHE_CONTROL="max-age=0"; export HTTP_CACHE_CONTROL

     8

HTTP_CONNECTION="keep-alive"; export HTTP_CONNECTION

     9

HTTP_HOST="hg.omnifarious.org"; export HTTP_HOST

    10

HTTP_KEEP_ALIVE="300"; export HTTP_KEEP_ALIVE

    11

HTTP_USER_AGENT="Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.0.4) Gecko/20060608 Ubuntu/dapper-security Firefox/1.5.0.4"; export HTTP_USER_AGENT

    12

PATH_INFO="/"; export PATH_INFO

    13

PATH_TRANSLATED="/var/www/hg/index.html"; export PATH_TRANSLATED

    14

QUERY_STRING=""; export QUERY_STRING

    15

REMOTE_ADDR="127.0.0.2"; export REMOTE_ADDR

    16

REMOTE_PORT="44703"; export REMOTE_PORT

    17

REQUEST_METHOD="GET"; export REQUEST_METHOD

    18

REQUEST_URI="/test/"; export REQUEST_URI

    19

SCRIPT_FILENAME="/home/hopper/hg_public/test.cgi"; export SCRIPT_FILENAME

    20

SCRIPT_NAME="/test"; export SCRIPT_NAME

    21

SCRIPT_URI="http://hg.omnifarious.org/test/"; export SCRIPT_URI

    22

SCRIPT_URL="/test/"; export SCRIPT_URL

    23

SERVER_ADDR="127.0.0.1"; export SERVER_ADDR

    24

SERVER_ADMIN="eric@localhost"; export SERVER_ADMIN

    25

SERVER_NAME="hg.omnifarious.org"; export SERVER_NAME

    26

SERVER_PORT="80"; export SERVER_PORT

    27

SERVER_PROTOCOL="HTTP/1.1"; export SERVER_PROTOCOL

    28

SERVER_SIGNATURE="<address>Apache/2.0.53 (Fedora) Server at hg.omnifarious.org Port 80</address>"; export SERVER_SIGNATURE

    29

SERVER_SOFTWARE="Apache/2.0.53 (Fedora)"; export SERVER_SOFTWARE