[groff] 13/13: [gdiffmk]: Skip tests if "diff -D" not supported.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 40739d1497c750aa4a0fc49c3c9f858b4aedf7b4
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Dec 25 19:13:03 2023 -0600

    [gdiffmk]: Skip tests if "diff -D" not supported.
    
    * contrib/gdiffmk/tests/runtests.sh: Test for "diff -D" support as
      gdiffmk itself does, and skip test if such support is lacking.
    
    * ANNOUNCE:
    * PROBLEMS: Drop caveat about potential test failures.
---
 ANNOUNCE                          |  5 -----
 PROBLEMS                          | 11 -----------
 contrib/gdiffmk/ChangeLog         |  5 +++++
 contrib/gdiffmk/tests/runtests.sh |  6 ++++++
 4 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/ANNOUNCE b/ANNOUNCE
index ca0e7b68f..54ecab5b9 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -133,11 +133,6 @@ sha256sum < groff-1.yy.0.tar.gz | cut -f1 -d\  | xxd -r -p 
| base64
 Caveats
 =======
 
-o Some portability issues are known to affect groff's gdiffmk utility.
-
-  gdiffmk does not work with BusyBox diff (which does not implement GNU
-  diff's "-D" option).
-
 o GNU tools, or otherwise POSIX-conforming ones, are generally required
   to build on Solaris 10 or 11.  See the "PROBLEMS" file in the
   distribution archive.
diff --git a/PROBLEMS b/PROBLEMS
index b5a832667..c8e479347 100644
--- a/PROBLEMS
+++ b/PROBLEMS
@@ -31,17 +31,6 @@ General Problems
 ================
 
 
-[groff 1.23.0]
-
-* gdiffmk doesn't work / its automated test fails.
-
-Some portability issues are known to affect groff's gdiffmk utility.
-
-- gdiffmk does not work with BusyBox diff (which does not implement GNU
-  diff's "-D" option).
-
-----------------------------------------------------------------------
-
 [groff 1.19.2]
 
 * When viewing man pages, some characters on my UTF-8 terminal emulator
diff --git a/contrib/gdiffmk/ChangeLog b/contrib/gdiffmk/ChangeLog
index aeeb76486..4d53aa2d0 100644
--- a/contrib/gdiffmk/ChangeLog
+++ b/contrib/gdiffmk/ChangeLog
@@ -1,3 +1,8 @@
+2023-12-25  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       * tests/runtests.sh: Test for "diff -D" support as gdiffmk
+       itself does, and skip test if such support is lacking.
+
 2023-12-23  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        * gdiffmk.sh (RequiresArgument): Refactor to use shell parameter
diff --git a/contrib/gdiffmk/tests/runtests.sh 
b/contrib/gdiffmk/tests/runtests.sh
index debd30ca0..1de1736a0 100755
--- a/contrib/gdiffmk/tests/runtests.sh
+++ b/contrib/gdiffmk/tests/runtests.sh
@@ -27,6 +27,12 @@
 
 gdiffmk=${abs_top_out_dir:-.}/gdiffmk
 
+if ! diff -Dx /dev/null /dev/null >/dev/null 2>&1
+then
+    echo "$0: diff command does not support -D option" >&2
+    exit 77 # skip
+fi
+
 # Locate directory containing our test artifacts.
 in_dir=