Re: [PATCH v9] Support auto-merge for meld to follow the vim-diff behavior

<lin.sun@zoom.us> writes:

The inner test does not make any sense to me; I doubt that you can get an empty output from a "git config --bool" that succeeds.

     $ cat >config <<\EOF
     [x] a
         b=true
         c=1
         d=false
         e=no
	 f=bogus
     EOF
     $ for i in a b c d e f
       do
         if v=$(git config --file=config --bool x.$i 2>/dev/null)
         then
           echo "succeeds (x.$i) => '$v'"
         else
           echo "fails (x.$i) => '$v'"
         fi
       done

You should see

succeeds (x.a) => 'true' succeeds (x.b) => 'true' succeeds (x.c) => 'true' succeeds (x.d) => 'false' succeeds (x.e) => 'false' fails (x.f) => ''

if you run the above. The most interesting is how all boolean values are normalized to true and false regardless of how they are originally spelled.

I think review by Đoàn pointed out that we would want to warn/fail loudly in this "else" case, as it is likely a misspelt configuration value?

To recap, I think something along the following lines would be the most readable and acceptably efficient with a short-cut for the common cases.

    var=mergetool.meld.whatever
    val=$(git config $var)
    case "$val" in
    true | false)
	# we can take a short-cut without asking config --bool
        ... use $val ...
	;;
    auto)
	... auto detect ...
	;;
    *)
	if val=$(git config --bool $var 2>/dev/null)
	then
		# succeeded, so val must be a normalized boolean
		... use $val ...
	else
		die cannot parse $var
	fi
    easc

Thanks.