tests/pdiff

packaging: bundle dulwich, keyring, and pywin32-ctypes with WiX too

TortoiseHg installs these, which is possibly where they originated (though I
would have thought it more likely to be in the WiX installer, given its
heritage).  When I was working on the TortoiseHg app for Mac (which uses the
similar `py2app`), it wasn't possible to use the keyring extension (even
externally) without bundling this keyring package into the app.  Assuming the
same principle applies here, these would enable some common extensions.  One of
the things that the TortoiseHg packager on macOS does now is it adds the user's
local `site-packages` directory to `sys.path`.  That would allow the user to
install these critical modules in cases like this.  But that can probably wait
for py3 packaging.

The only difference in the installed packages that I see now is WiX also bundles
distutils for some reason.  I suppose that's not harming anything, so I'm not
touching it.

The only orphans in the install directories when comparing WiX and Inno now is
the Copying.txt vs COPYING.rtf, the two uninstaller files for Inno, and a
`Mercurial.url` file in Inno.  I have no idea what that is, and it has *.ini
syntax with a single field pointing to the Mercurial homepage.

Differential Revision: https://phab.mercurial-scm.org/D8062

#!/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