Use diff's --strip-trailing-cr flag where appropriate on Windows

Test result files might be checked out using Unix or Windows style line
endings, depening on git flags, so on Windows we use the
--strip-trailing-cr flag to tell diff to ignore line endings
differences.

The flag is added to the diff invocation for the test_json_parser module
tests and the pg_bsd_indent tests. in pg_regress.c we replace the
current use of the "-w" flag, which ignore all white space differences,
with this one which only ignores line end differences.

Discussion: https://postgr.es/m/20240707052030.r77hbdkid3mwksop@awork3.anarazel.de

Author: adunstan

src/test/modules/test_json_parser/t/003_test_semantic.pl

@@ -29,7 +29,9 @@
 
 close($fh);
 
-($stdout, $stderr) = run_command([ "diff", "-u", $fname, $test_out ]);
+my @diffopts = ("-u");
+push(@diffopts, "--strip-trailing-cr") if $windows_os;
+($stdout, $stderr) = run_command([ "diff", @diffopts, $fname, $test_out ]);
 
 is($stdout, "", "no output diff");
 is($stderr, "", "no diff error");

src/test/regress/pg_regress.c

@@ -65,8 +65,8 @@ static char *shellprog = SHELLPROG;
 const char *basic_diff_opts = "";
 const char *pretty_diff_opts = "-U3";
 #else
-const char *basic_diff_opts = "-w";
-const char *pretty_diff_opts = "-w -U3";
+const char *basic_diff_opts = "--strip-trailing-cr";
+const char *pretty_diff_opts = "--strip-trailing-cr -U3";
 #endif
 
 /*

src/tools/pg_bsd_indent/t/001_pg_bsd_indent.pl

@@ -26,6 +26,10 @@
 # Any diffs in the generated files will be accumulated here.
 my $diffs_file = "test.diffs";
 
+# options used with diff
+my @diffopts = ("-upd");
+push(@diffopts, "--strip-trailing-cr") if $windows_os;
+
 # Copy support files to current dir, so *.pro files don't need to know path.
 while (my $file = glob("$src_dir/tests/*.list"))
 {
@@ -45,7 +49,7 @@
 		],
 		"pg_bsd_indent succeeds on $test");
 	# check result matches, adding any diff to $diffs_file
-	my $result = run_log([ 'diff', '-upd', "$test_src.stdout", "$test.out" ],
+	my $result = run_log([ 'diff', @diffopts, "$test_src.stdout", "$test.out" ],
 		'>>', $diffs_file);
 	ok($result, "pg_bsd_indent output matches for $test");
 }