Implement the roff(7) .shift and .return requests,

for example used by groff_hdtbl(7) and groff_mom(7).

Also correctly interpolate arguments during nested macro execution
even after .shift and .return, implemented using a stack of argument
arrays.

Note that only read.c, but not roff.c can detect the end of a macro
execution, and the existence of .shift implies that arguments cannot
be interpolated up front, so unfortunately, this includes a partial
revert of roff.c rev. 1.337, moving argument interpolation back into
the function roff_res().

1 files changed, 25 insertions, 0 deletions

diff --git a/regress/roff/shift/basic.out_ascii b/regress/roff/shift/basic.out_ascii
new file mode 100644
index 00000000..40675c67
--- /dev/null
+++ b/regress/roff/shift/basic.out_ascii
@@ -0,0 +1,25 @@
+SHIFT_BASIC(1)              General Commands Manual             SHIFT_BASIC(1)
+
+
+
+NNAAMMEE
+       sshhiifftt--bbaassiicc - the shift request
+
+DDEESSCCRRIIPPTTIIOONN
+       original arguments: oonnee_t_w_otthhrreeee_f_o_u_rffiivvee
+
+       after shift 2: tthhrreeee_f_o_u_rffiivvee
+
+       after shift without argument: ffoouurr_f_i_v_e
+
+       after shift 0: ffoouurr_f_i_v_e
+
+       expand to less than three bytes: <1>
+
+       expand to exactly three bytes: <x y>
+
+       expand to more than three bytes: <a longer argument... and another>
+
+
+
+OpenBSD                         August 23, 2018                 SHIFT_BASIC(1)