hgweb: log error before attempting I/O
Previously, an uncaught exception during HTTP request serving would
attempt to send an error response then log the exception.
If an exception occurred during I/O, this exception would be
raised and the original exception wouldn't be logged.
This commit changes behavior so the original exception is logged
first, before we attempt to do anything else. This ensures the
exception is logged.
This change resulted in new tracebacks appearing in various tests.
Because tracebacks can vary between Python versions, we added a
simple script to filter the stack part of traceback lines. This
makes testing much simpler, as we don't need to glob over lines
and make lines conditional.
Differential Revision: https://phab.mercurial-scm.org/D5749
#!/bin/sh
# Script to get stable diff output on any platform.
#
# Output of this script is almost equivalent to GNU diff with "-Nru".
#
# Use this script as "hg pdiff" via extdiff extension with preparation
# below in test scripts:
#
# $ cat >> $HGRCPATH <<EOF
# > [extdiff]
# > pdiff = sh "$RUNTESTDIR/pdiff"
# > EOF
filediff(){
# USAGE: filediff file1 file2 [header]
# compare with /dev/null if file doesn't exist (as "-N" option)
file1="$1"
if test ! -f "$file1"; then
file1=/dev/null
fi
file2="$2"
if test ! -f "$file2"; then
file2=/dev/null
fi
if cmp -s "$file1" "$file2" 2> /dev/null; then
# Return immediately, because comparison isn't needed. This
# also avoids redundant message of diff like "No differences
# encountered" (on Solaris)
return
fi
if test -n "$3"; then
# show header only in recursive case
echo "$3"
fi
# replace "/dev/null" by corresponded filename (as "-N" option)
diff -u "$file1" "$file2" |
sed "s@^--- /dev/null\(.*\)\$@--- $1\1@" |
sed "s@^\+\+\+ /dev/null\(.*\)\$@+++ $2\1@"
# in this case, files differ from each other
return 1
}
if test -d "$1" -o -d "$2"; then
# ensure comparison in dictionary order
(
if test -d "$1"; then (cd "$1" && find . -type f); fi
if test -d "$2"; then (cd "$2" && find . -type f); fi
) |
sed 's@^\./@@g' | sort | uniq |
while read file; do
filediff "$1/$file" "$2/$file" "diff -Nru $1/$file $2/$file"
done
# TODO: there is no portable way for current while-read based
# implementation to return 1 at detecting changes.
#
# On bash and dash, assignment to variable inside while-block
# doesn't affect outside, because inside while-block is executed
# in sub-shell. BTW, it affects outside while-block on ksh (as sh
# on Solaris).
else
filediff "$1" "$2"
fi