textutils-2.1, sort v2.0.14 question

I've seen what I consider to be weird sort behavior with sort v2.0.14.

(Weird, in that it does not agree with how I interpret the sort manual,
but maybe I am mis-interpreting the sort manual.)

1) Given the input 'garbled':
a
g g h i
i first
i three
a c d
c e g
i three x
i three m
c b
i second
i three a
ithreewords
i three words
i
ifirst
isecond

2) Sort produces this output, with the command `sort <garbled`:
a
a c d
c b
c e g
g g h i
i
ifirst
i first
isecond
i second
i three
i three a
i three m
ithreewords
i three words
i three x

3) But, the output that I expect can be produced with this command
`sort -k 1,1 <garbled`:
a
a c d
c b
c e g
g g h i
i
i first
i second
i three
i three a
i three m
i three words
i three x
ifirst
isecond
ithreewords


The manual states:

>     A pair of lines is compared as follows: if any key fields have been
> specified, `sort' compares each pair of fields, in the order specified on
> the command line, according to the associated ordering options, until a
> difference is found or no fields are left.  Unless otherwise specified,
> all comparisons use the character collating sequence specified by the
> `LC_COLLATE' locale.
> 
>    If any of the global options `bdfgiMnr' are given but no key fields
> are specified, `sort' compares the entire lines according to the global
> options.
> 
>    Finally, as a last resort when all keys compare equal (or if no
> ordering options were specified at all), `sort' compares the entire
> lines.  The last resort comparison honors the `--reverse' (`-r') global
> option.  The `--stable' (`-s') option disables this last-resort
> comparison so that lines in which all fields compare equal are left in
> their original relative order.  If no fields or global options are
> specified, `--stable' (`-s') has no effect

As I understand it, in example '2)' above, no keys are specified, and
I would expect the output that example '3)' produces.

Is there some reasoning as to why example '2)' produces the output it
does that I am missing?

(Note: These results are from the tarball textutils-2.1.tar.gz, and that
I compiled and ran on RedHat 7.2, if that's important. )


Thank-you for any help,
Jason