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

tglsfdc · tglsfdc · commit 90b418f81645 · 2020-07-09T16:02:23.000-04:00
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 1c4e88e 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
diff --git a/src/backend/utils/adt/misc.c b/src/backend/utils/adt/misc.c
@@ -17,6 +17,7 @@
 #include <sys/file.h>
 #include <signal.h>
 #include <dirent.h>
+#include <fcntl.h>
 #include <math.h>
 #include <unistd.h>
 
@@ -930,9 +931,6 @@ pg_current_logfile(PG_FUNCTION_ARGS)
 	FILE	   *fd;
 	char		lbuffer[MAXPGPATH];
 	char	   *logfmt;
-	char	   *log_filepath;
-	char	   *log_format = lbuffer;
-	char	   *nlpos;
 
 	/* The log format parameter is optional */
 	if (PG_NARGS() == 0 || PG_ARGISNULL(0))
@@ -959,16 +957,23 @@ pg_current_logfile(PG_FUNCTION_ARGS)
 		PG_RETURN_NULL();
 	}
 
+#ifdef WIN32
+	/* syslogger.c writes CRLF line endings on Windows */
+	_setmode(_fileno(fd), _O_TEXT);
+#endif
+
 	/*
 	 * Read the file to gather current log filename(s) registered by the
 	 * syslogger.
 	 */
 	while (fgets(lbuffer, sizeof(lbuffer), fd) != NULL)
 	{
-		/*
-		 * Extract log format and log file path from the line; lbuffer ==
-		 * log_format, they share storage.
-		 */
+		char	   *log_format;
+		char	   *log_filepath;
+		char	   *nlpos;
+
+		/* Extract log format and log file path from the line. */
+		log_format = lbuffer;
 		log_filepath = strchr(lbuffer, ' ');
 		if (log_filepath == NULL)
 		{
