[ms]: Port a test to Solaris 11 sed.

* tmac/tests/s_TC-works-with-percent-in-custom-titles.sh: Put newlines
  after opening braces in sed scripts.  macOS and GNU sed tolerate their
  absence, but this sed does not.

* HACKING: Document this problem.

ChangeLog

@@ -1,3 +1,12 @@
+2023-02-16  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+	[ms]: Port a test to Solaris 11 sed.
+
+	* tmac/tests/s_TC-works-with-percent-in-custom-titles.sh: Put
+	newlines after opening braces in sed scripts.  macOS and GNU sed
+	tolerate their absence, but this sed does not.
+	* HACKING: Document this problem.
+
 2023-02-16  G. Branden Robinson <g.branden.robinson@gmail.com>
 
 	* src/roff/groff/groff.am (groff_TESTS) [!USE_GROHTML]: Don't

HACKING

@@ -113,6 +113,8 @@ Here are some portability notes on writing automated tests.
   as follows.
     sed -n '/Foo\./{n;s/^$/FAILURE/;p;}'
 
+  But see below regarding the opening braces.
+
 * POSIX doesn't say that sed has to accept semicolons as command
   separators after label (':') and branch ('t') commands, or after brace
   commands, so macOS sed doesn't.  GNU sed does.
@@ -125,12 +127,26 @@ Here are some portability notes on writing automated tests.
       -e 's/.*/SUCCESS/;:A;' \
       -e 'p;}')
 
+  But see below regarding the opening braces.
+
   Similarly, a brace sequence like that in this partial sed script:
     /f1/p}}}}}}
-  must be rewritten as follows.
+  must be rewritten as follows (or with '-e' expressions).
     /f1/p;}
     }
     }
     }
     }
     }
+
+* macOS and GNU sed don't require newlines (or '-e' expression endings)
+  after _opening_ braces, but Solaris 11 sed does.
+
+  So the sed script
+    /i/{N;/Table of Contents/{N;/Foo[. ][. ]*1/p;};}
+  must be rewritten as follows (or with '-e' expressions).
+    /i/{
+    N;/Table of Contents/{
+    N;/Foo[. ][. ]*1/p;
+    };
+    }

tmac/tests/s_TC-works-with-percent-in-custom-titles.sh

@@ -42,7 +42,11 @@ OUTPUT=$(echo "$EXAMPLE" | "$groff" -Tascii -P-cbou -ms)
 # test is the presence, adjacency, and ordering of non-blank lines.
 FILTERED_OUTPUT=$(echo "$OUTPUT" \
     | sed '/^$/d' \
-    | sed -n '/i/{N;/Table of Contents/{N;/Foo[. ][. ]*1/p;};}')
+    | sed -n '/i/{
+N;/Table of Contents/{
+N;/Foo[. ][. ]*1/p;
+};
+}')
 test -n "$FILTERED_OUTPUT"
 
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