Patch the select extension set_non_blocking function to work with a single "" argument.

4 files changed, 29 insertions, 6 deletions

diff --git a/ChangeLog b/ChangeLog
index a692e5b1..8fc992d3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-07-05         Andrew J. Schorr     <aschorr@telemetry-investments.com>
+
+	* gawkapi.h (gawk_api): Document that the api_get_file function will not
+	access the file type and length arguments if the file name is empty.
+
 2013-07-04         Andrew J. Schorr     <aschorr@telemetry-investments.com>
 
 	* configure.ac (AC_CHECK_FUNCS): Add a check for waitpid.
diff --git a/extension/ChangeLog b/extension/ChangeLog
index 4108f74c..68ba6fe2 100644
--- a/extension/ChangeLog
+++ b/extension/ChangeLog
@@ -1,5 +1,11 @@
 2013-07-05         Andrew J. Schorr     <aschorr@telemetry-investments.com>
 
+	* select.c (set_non_blocking): Do not attempt F_SETFL if F_GETFL fails.
+	(do_set_non_blocking): Add support for case when called with a single
+	"" argument.
+
+2013-07-05         Andrew J. Schorr     <aschorr@telemetry-investments.com>
+
 	* select.c (do_signal): If sigaction is unavailable, fall back to
 	signal and hope that it does the right thing.
 
diff --git a/extension/select.c b/extension/select.c
index 44b60d50..4d28457d 100644
--- a/extension/select.c
+++ b/extension/select.c
@@ -413,11 +413,14 @@ do_select(int nargs, awk_value_t *result)
 static int
 set_non_blocking(int fd)
 {
-	int flags = fcntl(fd, F_GETFL);
-	int rc = fcntl(fd, F_SETFL, (flags|O_NONBLOCK));
-	if (rc < 0)
+	int flags;
+
+	if (((flags = fcntl(fd, F_GETFL)) == -1) ||
+		(fcntl(fd, F_SETFL, (flags|O_NONBLOCK)) == -1)) {
 		update_ERRNO_int(errno);
-	return rc;
+		return -1;
+	}
+	return 0;
 }
 
 /*  do_set_non_blocking --- Set a file to be non-blocking */
@@ -430,12 +433,19 @@ do_set_non_blocking(int nargs, awk_value_t *result)
 
 	if (do_lint && nargs > 2)
 		lintwarn(ext_id, _("set_non_blocking: called with too many arguments"));
+	/*
+	 * N.B. If called with a single "" arg, we want it to work!  In that
+	 * case, the 1st arg is an empty string, and get_argument fails on the
+	 * 2nd arg.  Note that API get_file promises not to access the type
+	 * argument if the name argument is an empty string.
+	 */
 	if (get_argument(0, AWK_NUMBER, & cmd) &&
 		(cmd.num_value == (fd = cmd.num_value)) && 
 		! get_argument(1, AWK_STRING, & cmdtype))
 		return make_number(set_non_blocking(fd), result);
 	else if (get_argument(0, AWK_STRING, & cmd) &&
-		get_argument(1, AWK_STRING, & cmdtype)) {
+		(get_argument(1, AWK_STRING, & cmdtype) ||
+			(! cmd.str_value.len && (nargs == 1)))) {
 		const awk_input_buf_t *buf;
 		if ((buf = get_file(cmd.str_value.str, cmd.str_value.len, cmdtype.str_value.str, cmdtype.str_value.len)) != NULL)
 			return make_number(set_non_blocking(buf->fd), result);
diff --git a/gawkapi.h b/gawkapi.h
index 687147e3..51374d9f 100644
--- a/gawkapi.h
+++ b/gawkapi.h
@@ -668,7 +668,9 @@ typedef struct gawk_api {
 
 	/*
 	 * Look up a file.  If the name is NULL or name_len is 0, it returns
-	 * data for the currently open input file corresponding to FILENAME.
+	 * data for the currently open input file corresponding to FILENAME
+	 * (and it will not access the filetype or typelen arguments, so those
+	 * may be undefined).
 	 * If the file is not already open, it tries to open it.
 	 * The "filetype" argument should be one of:
 	 *    ">", ">>", "<", "|>", "|<", and "|&"