Fix pg_current_logfile() to not emit a carriage return on Windows.

Due to not having our signals straight about CRLF vs. LF line
termination, the output of pg_current_logfile() included a trailing
\r on Windows.  To fix, force the file descriptor it uses into text
mode.

While here, move a couple of local variable declarations to make
the function's logic clearer.

In v12 and v13, also back-patch the test added by 1c4e88e2f so that
this function has some test coverage.  However, the 004_logrotate.pl
test script doesn't exist before v12, and it didn't seem worth adding
to older branches just for this.

Per report from Thomas Kellerer.  Back-patch to v10 where this
function was added.

Discussion: https://postgr.es/m/412ae8da-76bb-640f-039a-f3513499e53d@gmx.net

1 files changed, 5 insertions, 1 deletions

diff --git a/src/bin/pg_ctl/t/004_logrotate.pl b/src/bin/pg_ctl/t/004_logrotate.pl
index 71dbfd20301..acaade8d812 100644
--- a/src/bin/pg_ctl/t/004_logrotate.pl
+++ b/src/bin/pg_ctl/t/004_logrotate.pl
@@ -3,7 +3,7 @@ use warnings;
 
 use PostgresNode;
 use TestLib;
-use Test::More tests => 4;
+use Test::More tests => 5;
 use Time::HiRes qw(usleep);
 
 # Set up node with logging collector
@@ -47,6 +47,10 @@ for (my $attempts = 0; $attempts < $max_attempts; $attempts++)
 
 like($first_logfile, qr/division by zero/, 'found expected log file content');
 
+# While we're at it, test pg_current_logfile() function
+is($node->safe_psql('postgres', "SELECT pg_current_logfile('stderr')"),
+	$lfname, 'pg_current_logfile() gives correct answer');
+
 # Sleep 2 seconds and ask for log rotation; this should result in
 # output into a different log file name.
 sleep(2);