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st (suckless terminal) config 

Fix ttywrite()

ttywrite was assuming that if it could not write then it could
read, but this is not necessarily true, there are some situations
where you cannot read or write. The correct behaviour is to detect
if you can read or/and write.
Roberto E. Vargas Caballero k0ga@shike2.com
commit

9f6d8845df3f81e2bc86f593a2f93e098422b2fa

parent

f0398db4d172e838ef4b4ae55db3fb6a6fee6717

1 files changed, 20 insertions(+), 18 deletions(-)

jump to
M st.c → st.c 
@@ -415,7 +415,7 @@ static int32_t tdefcolor(int *, int *, int);
 static void tdeftran(char);
 static inline int match(uint, uint);
 static void ttynew(void);
-static void ttyread(void);
+static size_t ttyread(void);
 static void ttyresize(void);
 static void ttysend(char *, size_t);
 static void ttywrite(const char *, size_t);

@@ -1464,7 +1464,7 @@ break;
 	}
 }
 
-void
+size_t
 ttyread(void)
 {
 	static char buf[BUFSIZ];

@@ -1489,14 +1489,16 @@ }
 
 	/* keep any uncomplete utf8 char for the next call */
 	memmove(buf, ptr, buflen);
+
+	return ret;
 }
 
 void
 ttywrite(const char *s, size_t n)
 {
-	fd_set wfd;
-	struct timespec tv;
+	fd_set wfd, rfd;
 	ssize_t r;
+	size_t lim = 256;
 
 	/*
 	 * Remember that we are using a pty, which might be a modem line.

@@ -1506,38 +1508,34 @@ * FIXME: Migrate the world to Plan 9.
 	 */
 	while (n > 0) {
 		FD_ZERO(&wfd);
+		FD_ZERO(&rfd);
 		FD_SET(cmdfd, &wfd);
-		tv.tv_sec = 0;
-		tv.tv_nsec = 0;
+		FD_SET(cmdfd, &rfd);
 
 		/* Check if we can write. */
-		if (pselect(cmdfd+1, NULL, &wfd, NULL, &tv, NULL) < 0) {
+		if (pselect(cmdfd+1, &rfd, &wfd, NULL, NULL, NULL) < 0) {
 			if (errno == EINTR)
 				continue;
 			die("select failed: %s\n", strerror(errno));
 		}
-		if(!FD_ISSET(cmdfd, &wfd)) {
-			/* No, then free some buffer space. */
-			ttyread();
-		} else {
+		if (FD_ISSET(cmdfd, &rfd))
+			lim = ttyread();
+		if (FD_ISSET(cmdfd, &wfd)) {
 			/*
 			 * Only write 256 bytes at maximum. This seems to be a
 			 * reasonable value for a serial line. Bigger values
 			 * might clog the I/O.
 			 */
-			r = write(cmdfd, s, (n < 256)? n : 256);
-			if (r < 0) {
-				die("write error on tty: %s\n",
-						strerror(errno));
-			}
+			if ((r = write(cmdfd, s, (n < 256)? n : 256)) < 0)
+				goto write_error;
 			if (r < n) {
 				/*
 				 * We weren't able to write out everything.
 				 * This means the buffer is getting full
 				 * again. Empty it.
 				 */
-				if (n < 256)
-					ttyread();
+				if (n < lim)
+					lim = ttyread();
 				n -= r;
 				s += r;
 			} else {

@@ -1546,6 +1544,10 @@ break;
 			}
 		}
 	}
+	return;
+
+write_error:
+	die("write error on tty: %s\n", strerror(errno));
 }
 
 void