view tests/pdiff @ 39286:3c4b2e880273

log: respect graphshorten on terminal nodes (collapsing o-~ to just o~)

Internally we have a custom template that's inspired by ones that we have seen
in the community. Normally, this looks something like:

    o  0834ec17 spectral tip
    |  crecord: support x to toggle single, X to toggle a range
    o  ee932990 spectral @
    |  filemerge: allow specifying $hgeditor as merge-tools.X.executable
    @  66f04611 matt_harbison
    |  cext: fix truncation warnings in revlog on Windows
    o  42cc76d0 matt_harbison
    |  cext: fix revlog compiler error on Windows
    ~
    o  bd63ada7 stable boris
    |  phases: drop dead code in `newheads`
    ~

With graphshorten on, and the descriptions of the public nodes hidden, it looks
like this, note that the commits right before the ~ are still "full height":

    o  0834ec17 spectral tip
    |  crecord: support x to toggle single, X to toggle a range
    o  ee932990 spectral @
    |  filemerge: allow specifying $hgeditor as merge-tools.X.executable
    @  66f04611 matt_harbison
    o  42cc76d0 matt_harbison
    |
    ~
    o  bd63ada7 stable boris
    |
    ~

This patch makes them look like this, removing the | but keeping the ~:

    o  0834ec17 spectral tip
    |  crecord: support x to toggle single, X to toggle a range
    o  ee932990 spectral @
    |  filemerge: allow specifying $hgeditor as merge-tools.X.executable
    @  66f04611 matt_harbison
    o  42cc76d0 matt_harbison
    ~
    o  bd63ada7 stable boris
    ~

This originally removed the ~s entirely, but this was determined to be too much
information loss and potentially confusing. This would have looked like the
following (note that the last commit is on a different branch than all of the
ones above it, and they are *not* linearly related):

    o  0834ec17 spectral tip
    |  crecord: support x to toggle single, X to toggle a range
    o  ee932990 spectral @
    |  filemerge: allow specifying $hgeditor as merge-tools.X.executable
    @  66f04611 matt_harbison
    o  42cc76d0 matt_harbison
    o  bd63ada7 stable boris

Differential Revision: https://phab.mercurial-scm.org/D4363

#!/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