[mm]: Regression-test Savannah #54909.

* contrib/mm/tests/P-indentation-works.sh: Do it.
* contrib/mm/mm.am (mm_TESTS): Run test.

Test fails at this commit (cases 8 and 10 of 11, paragraph indentation
after displays and lists).

3 files changed, 143 insertions, 0 deletions

diff --git a/contrib/mm/ChangeLog b/contrib/mm/ChangeLog
index e515eb600..89525546f 100644
--- a/contrib/mm/ChangeLog
+++ b/contrib/mm/ChangeLog
@@ -1,5 +1,12 @@
 2023-01-24  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+	Regression-test Savannah #54909.
+
+	* tests/P-indentation-works.sh: Do it.
+	* mm.am (mm_TESTS): Run test.
+
+2023-01-24  G. Branden Robinson <g.branden.robinson@gmail.com>
+
 	* m.tmac (df@print-float): Eliminate spew at high debug levels.
 	This macro gets called even when there aren't any floating
 	displays pending, so we cannot assume that related registers are
diff --git a/contrib/mm/mm.am b/contrib/mm/mm.am
index 6c037bfce..191dbce44 100644
--- a/contrib/mm/mm.am
+++ b/contrib/mm/mm.am
@@ -65,6 +65,7 @@ mm_TESTS = \
   contrib/mm/tests/LT_SP_multi-word_LO_SJ_works.sh \
   contrib/mm/tests/MT-1-reports-all-TM-numbers.sh \
   contrib/mm/tests/MT_5_includes_AT_in_SG.sh \
+  contrib/mm/tests/P-indentation-works.sh \
   contrib/mm/tests/ms_cover_sheet_robust_to_missing_AF.sh \
   contrib/mm/tests/mse_has-sufficient-footnote-space.sh \
   contrib/mm/tests/place-equation-labels-correctly-in-displays.sh \
diff --git a/contrib/mm/tests/P-indentation-works.sh b/contrib/mm/tests/P-indentation-works.sh
new file mode 100755
index 000000000..5be7efdc5
--- /dev/null
+++ b/contrib/mm/tests/P-indentation-works.sh
@@ -0,0 +1,135 @@
+#!/bin/sh
+#
+# Copyright (C) 2023 Free Software Foundation, Inc.
+#
+# This file is part of groff.
+#
+# groff is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# groff is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+groff="${abs_top_builddir:-.}/test-groff"
+
+fail=
+
+wail () {
+    echo ...FAILED >&2
+    fail=YES
+}
+
+# Regression-test Savannah #54909.  Check other cases as well.
+
+input='.P
+P1 not indented.
+.P 0
+P2 not indented.
+.P 1
+P3 indented.
+.nr Pt 2
+.P
+P4 indented.
+.H 1 Heading
+.P
+P5 not indented.
+.P
+P6 indented.
+.H 3 "Run-in heading."
+Some text.
+.P
+P7 indented.
+.DS
+display
+.DE
+.P
+P8 not indented.
+.P
+P9 indented.
+.BL
+.LI
+list item
+.LE
+.P
+P10 not indented.
+.P
+P11 indented.'
+
+output=$(printf "%s\n" "$input" | "$groff" -mm -Tascii -P-cbou)
+echo "$output"
+
+#       P1 not indented.
+#
+#       P2 not indented.
+#
+#            P3 indented.
+#
+#            P4 indented.
+#
+#
+#       1.  Heading
+#
+#       P5 not indented.
+#
+#            P6 indented.
+#
+#       1.0.1  Run-in heading.  Some text.
+#
+#            P7 indented.
+#
+#       display
+#
+#       P8 not indented.
+#
+#            P9 indented.
+#
+#          o list item
+#
+#       P10 not indented.
+#
+#            P11 indented.
+
+echo "checking that initial untyped paragraph not indented" >&2
+echo "$output" | grep -Eqx ' {7}P1 not indented\.' || wail
+
+echo "checking that initial type 0 paragraph not indented" >&2
+echo "$output" | grep -Eqx ' {7}P2 not indented\.' || wail
+
+echo "checking that first paragraph after Pt=2 indented" >&2
+echo "$output" | grep -Eqx ' {12}P3 indented\.' || wail
+
+echo "checking that second paragraph after Pt=2 indented" >&2
+echo "$output" | grep -Eqx ' {12}P4 indented\.' || wail
+
+echo "checking that first paragraph after heading not indented" >&2
+echo "$output" | grep -Eqx ' {7}P5 not indented\.' || wail
+
+echo "checking that second paragraph after heading indented" >&2
+echo "$output" | grep -Eqx ' {12}P6 indented\.' || wail
+
+echo "checking that paragraph after run-in heading indented" >&2
+echo "$output" | grep -Eqx ' {12}P7 indented\.' || wail
+
+echo "checking that first paragraph after display not indented" >&2
+echo "$output" | grep -Eqx ' {7}P8 not indented\.' || wail
+
+echo "checking that second paragraph after display indented" >&2
+echo "$output" | grep -Eqx ' {12}P9 indented\.' || wail
+
+echo "checking that first paragraph after list not indented" >&2
+echo "$output" | grep -Eqx ' {7}P10 not indented\.' || wail
+
+echo "checking that second paragraph after list indented" >&2
+echo "$output" | grep -Eqx ' {12}P11 indented\.' || wail
+
+test -z "$fail"
+
+# vim:set ai et sw=4 ts=4 tw=72: