When .Sm is called without an argument, groff toggles the spacing mode,

so let us do the same for compatibility.  Using this feature is of
course not recommended except in manual page obfuscation contests.

1 files changed, 8 insertions, 3 deletions

diff --git a/mdoc.7 b/mdoc.7
index 5452ca49..49b93037 100644
--- a/mdoc.7
+++ b/mdoc.7
@@ -468,7 +468,7 @@ in the alphabetical
 .It Sx \&Pf Ta prefix, no following horizontal space (one argument)
 .It Sx \&Ns Ta roman font, no preceding horizontal space (no arguments)
 .It Sx \&Ap Ta apostrophe without surrounding whitespace (no arguments)
-.It Sx \&Sm Ta switch horizontal spacing mode: Cm on | off
+.It Sx \&Sm Ta switch horizontal spacing mode: Op Cm on | off
 .It Sx \&Bk , \&Ek Ta keep block: Fl words
 .It Sx \&br Ta force output line break in text mode (no arguments)
 .It Sx \&sp Ta force vertical space: Op Ar height
@@ -2335,7 +2335,7 @@ and
 Switches the spacing mode for output generated from macros.
 Its syntax is as follows:
 .Pp
-.D1 Pf \. Sx \&Sm Cm on | off
+.D1 Pf \. Sx \&Sm Op Cm on | off
 .Pp
 By default, spacing is
 .Cm on .
@@ -2344,6 +2344,11 @@ When switched
 no white space is inserted between macro arguments and between the
 output generated from adjacent macros, but text lines
 still get normal spacing between words and sentences.
+.Pp
+When called without an argument, the
+.Sx \&Sm
+macro toggles the spacing mode.
+Using this is not recommended because it makes the code harder to read.
 .Ss \&So
 Multi-line version of
 .Sx \&Sq .
@@ -3022,7 +3027,7 @@ then the macro accepts an arbitrary number of arguments.
 .It Sx \&Pf  Ta    Yes      Ta    Yes      Ta    1
 .It Sx \&Pp  Ta    \&No     Ta    \&No     Ta    0
 .It Sx \&Rv  Ta    \&No     Ta    \&No     Ta    n
-.It Sx \&Sm  Ta    \&No     Ta    \&No     Ta    1
+.It Sx \&Sm  Ta    \&No     Ta    \&No     Ta    <2
 .It Sx \&St  Ta    \&No     Ta    Yes      Ta    1
 .It Sx \&Sx  Ta    Yes      Ta    Yes      Ta    >0
 .It Sx \&Sy  Ta    Yes      Ta    Yes      Ta    >0