[man pages]: Define page-local `MR` fallback.

[man pages]: Provide page-local fallback definition of new `MR` macro.
I didn't think I was going to have to do this, but the premier site on
the web for viewing Linux man pages, Michael Kerrisk's man7.org, has
been pulling snapshots of the pages themselves without upgrading the
underlying macros, and so man page cross references set with `MR` are
getting lost in its presentations.  (I acknowledge: Ingo Schwarze warned
me something like this could happen.)  This definition is intended as a
stopgap measure only.  I want to revert this after groff 1.23 is
released and has spread to some reasonable degree.

* contrib/chem/chem.1.man:
* contrib/eqn2graph/eqn2graph.1.man:
* contrib/gdiffmk/gdiffmk.1.man:
* contrib/glilypond/glilypond.1.man:
* contrib/gperl/gperl.1.man:
* contrib/gpinyin/gpinyin.1.man:
* contrib/grap2graph/grap2graph.1.man:
* contrib/hdtbl/groff_hdtbl.7.man:
* contrib/mm/groff_mm.7.man:
* contrib/mm/groff_mmse.7.man:
* contrib/mm/mmroff.1.man:
* contrib/mom/groff_mom.7.man:
* contrib/pdfmark/pdfroff.1.man:
* contrib/pic2graph/pic2graph.1.man:
* contrib/rfc1345/groff_rfc1345.7.man:
* man/groff.7.man:
* man/groff_char.7.man:
* man/groff_diff.7.man:
* man/groff_font.5.man:
* man/groff_out.5.man:
* man/groff_tmac.5.man:
* man/roff.7.man:
* src/devices/grodvi/grodvi.1.man:
* src/devices/grohtml/grohtml.1.man:
* src/devices/grolbp/grolbp.1.man:
* src/devices/grolj4/grolj4.1.man:
* src/devices/gropdf/gropdf.1.man:
* src/devices/gropdf/pdfmom.1.man:
* src/devices/grops/grops.1.man:
* src/devices/grotty/grotty.1.man:
* src/devices/xditview/gxditview.1.man:
* src/preproc/eqn/eqn.1.man:
* src/preproc/eqn/neqn.1.man:
* src/preproc/grn/grn.1.man:
* src/preproc/pic/pic.1.man:
* src/preproc/preconv/preconv.1.man:
* src/preproc/refer/refer.1.man:
* src/preproc/soelim/soelim.1.man:
* src/preproc/tbl/tbl.1.man:
* src/roff/groff/groff.1.man:
* src/roff/nroff/nroff.1.man:
* src/roff/troff/troff.1.man:
* src/utils/addftinfo/addftinfo.1.man:
* src/utils/afmtodit/afmtodit.1.man:
* src/utils/grog/grog.1.man:
* src/utils/hpftodit/hpftodit.1.man:
* src/utils/indxbib/indxbib.1.man:
* src/utils/lkbib/lkbib.1.man:
* src/utils/lookbib/lookbib.1.man:
* src/utils/pfbtops/pfbtops.1.man:
* src/utils/tfmtodit/tfmtodit.1.man:
* src/utils/xtotroff/xtotroff.1.man:
* tmac/groff_man.7.man.in:
* tmac/groff_me.7.man:
* tmac/groff_ms.7.man:
* tmac/groff_trace.7.man:
* tmac/groff_www.7.man: Do it.

The sed script I used follows.  I patched neqn(1), which does not
require compatibility mode, by hand.

/^\.cp 0/a\
.\
.\\" Define fallback for groff 1.23's MR macro if the system lacks it.\
.de @@\
.  de MR\
.    ie \\n(.$=1 \\\
.      I \%\\$1\
.    el \\\
.      IR \%\\$1 (\\$2)\\$3\
.  \\\\.\
..\
.if  \\n(.g .if !d MR .@@\
.if !\\n(.g .@@\
.rm @@

15 files changed, 195 insertions, 0 deletions

diff --git a/contrib/chem/chem.1.man b/contrib/chem/chem.1.man
index 78b55cab6..78efd86e9 100644
--- a/contrib/chem/chem.1.man
+++ b/contrib/chem/chem.1.man
@@ -26,6 +26,19 @@ documents
 .do nr *groff_chem_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/eqn2graph/eqn2graph.1.man b/contrib/eqn2graph/eqn2graph.1.man
index 697163fc4..fb8c82593 100644
--- a/contrib/eqn2graph/eqn2graph.1.man
+++ b/contrib/eqn2graph/eqn2graph.1.man
@@ -16,6 +16,19 @@ equation into a cropped image
 .do nr *groff_eqn2graph_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/gdiffmk/gdiffmk.1.man b/contrib/gdiffmk/gdiffmk.1.man
index 325b09cc1..4680821c5 100644
--- a/contrib/gdiffmk/gdiffmk.1.man
+++ b/contrib/gdiffmk/gdiffmk.1.man
@@ -33,6 +33,19 @@ files
 .do nr *groff_gdiffmk_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/glilypond/glilypond.1.man b/contrib/glilypond/glilypond.1.man
index 6bb5e9941..a41469ad2 100644
--- a/contrib/glilypond/glilypond.1.man
+++ b/contrib/glilypond/glilypond.1.man
@@ -28,6 +28,19 @@ documents
 .do nr *groff_glilypond_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/gperl/gperl.1.man b/contrib/gperl/gperl.1.man
index ed8f04264..35643f5d3 100644
--- a/contrib/gperl/gperl.1.man
+++ b/contrib/gperl/gperl.1.man
@@ -26,6 +26,19 @@ documents
 .do nr *groff_gperl_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/gpinyin/gpinyin.1.man b/contrib/gpinyin/gpinyin.1.man
index e50d6ab61..e479d8074 100644
--- a/contrib/gpinyin/gpinyin.1.man
+++ b/contrib/gpinyin/gpinyin.1.man
@@ -27,6 +27,19 @@ documents
 .do nr *groff_gpinyin_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .\" Local definitions
diff --git a/contrib/grap2graph/grap2graph.1.man b/contrib/grap2graph/grap2graph.1.man
index 7aecc350c..bb5eea760 100644
--- a/contrib/grap2graph/grap2graph.1.man
+++ b/contrib/grap2graph/grap2graph.1.man
@@ -16,6 +16,19 @@ diagram into a cropped image
 .do nr *groff_grap2graph_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/hdtbl/groff_hdtbl.7.man b/contrib/hdtbl/groff_hdtbl.7.man
index 315b01a28..af9e15c3e 100644
--- a/contrib/hdtbl/groff_hdtbl.7.man
+++ b/contrib/hdtbl/groff_hdtbl.7.man
@@ -26,6 +26,19 @@ groff_hdtbl \- Heidelberger table macros for GNU
 .do nr *groff_groff_hdtbl_7_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .ig
   Some simple formatting macros.  Note that we use '.ig' here and not a
diff --git a/contrib/mm/groff_mm.7.man b/contrib/mm/groff_mm.7.man
index 47800f41c..d7f5ab156 100644
--- a/contrib/mm/groff_mm.7.man
+++ b/contrib/mm/groff_mm.7.man
@@ -31,6 +31,19 @@ groff_mm \- memorandum macros for GNU
 .do nr *groff_groff_mm_7_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/mm/groff_mmse.7.man b/contrib/mm/groff_mmse.7.man
index 4e75b621d..605aec81c 100644
--- a/contrib/mm/groff_mmse.7.man
+++ b/contrib/mm/groff_mmse.7.man
@@ -32,6 +32,19 @@ groff_mmse \- svenska \(rqmemorandum\(rq makro f\(:or GNU
 .do nr *groff_groff_mmse_7_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Syntax
diff --git a/contrib/mm/mmroff.1.man b/contrib/mm/mmroff.1.man
index c35b46e38..e47957ce2 100644
--- a/contrib/mm/mmroff.1.man
+++ b/contrib/mm/mmroff.1.man
@@ -31,6 +31,19 @@ macro package
 .do nr *groff_mmroff_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/mom/groff_mom.7.man b/contrib/mom/groff_mom.7.man
index a4c2d8639..0b4492358 100644
--- a/contrib/mom/groff_mom.7.man
+++ b/contrib/mom/groff_mom.7.man
@@ -32,6 +32,19 @@ groff_mom \- modern macros for document composition with GNU
 .do nr *groff_groff_mom_7_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .\" Setup
diff --git a/contrib/pdfmark/pdfroff.1.man b/contrib/pdfmark/pdfroff.1.man
index a49fa3909..41ea4f504 100644
--- a/contrib/pdfmark/pdfroff.1.man
+++ b/contrib/pdfmark/pdfroff.1.man
@@ -26,6 +26,19 @@ pdfroff \- construct files in Portable Document Format using
 .do nr *groff_pdfroff_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/pic2graph/pic2graph.1.man b/contrib/pic2graph/pic2graph.1.man
index 571a520f2..f65aa88fe 100644
--- a/contrib/pic2graph/pic2graph.1.man
+++ b/contrib/pic2graph/pic2graph.1.man
@@ -16,6 +16,19 @@ diagram into a cropped image
 .do nr *groff_pic2graph_1_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Synopsis
diff --git a/contrib/rfc1345/groff_rfc1345.7.man b/contrib/rfc1345/groff_rfc1345.7.man
index 9998e1690..c05fef96c 100644
--- a/contrib/rfc1345/groff_rfc1345.7.man
+++ b/contrib/rfc1345/groff_rfc1345.7.man
@@ -35,6 +35,19 @@ groff_rfc1345 \- special character names from RFC 1345 and Vim digraphs
 .do nr *groff_groff_rfc1345_7_man_C \n[.cp]
 .cp 0
 .
+.\" Define fallback for groff 1.23's MR macro if the system lacks it.
+.de @@
+.  de MR
+.    ie \n(.$=1 \
+.      I %\$1
+.    el \
+.      IR %\$1 (\$2)\$3
+.  \\.
+..
+.if  \n(.g .if !d MR .@@
+.if !\n(.g .@@
+.rm @@
+.
 .
 .\" ====================================================================
 .SH Description