lib: fix CRNL causing empty prompt lines

CR, NL and CRNL are all OK, but CRNL shouldn't get treated as 2
newlines (which causes an empty command to be executed => empty prompt
line.)

Signed-off-by: David Lamparter <equinox@diac24.net>

diff --git a/lib/vty.c b/lib/vty.c
index 2a7154788486808df2844f9ea8e730693942edf7..65f8d78a965f4125ab4ac617d21e753e7f4afb30 100644 (file)
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -1285,6 +1285,7 @@ static int vty_execute(struct vty *vty)
 #define VTY_NORMAL     0
 #define VTY_PRE_ESCAPE 1
 #define VTY_ESCAPE     2
+#define VTY_CR         3
 
 /* Escape character command map. */
 static void vty_escape_map(unsigned char c, struct vty *vty)
@@ -1423,6 +1424,17 @@ static int vty_read(struct thread *thread)
                        continue;
                }
 
+               if (vty->escape == VTY_CR) {
+                       /* if we get CR+NL, the NL results in an extra empty
+                        * prompt line being printed without this;  just drop
+                        * the NL if it immediately follows CR.
+                        */
+                       vty->escape = VTY_NORMAL;
+
+                       if (buf[i] == '\n')
+                               continue;
+               }
+
                switch (buf[i]) {
                case CONTROL('A'):
                        vty_beginning_of_line(vty);
@@ -1467,8 +1479,10 @@ static int vty_read(struct thread *thread)
                case CONTROL('Z'):
                        vty_end_config(vty);
                        break;
-               case '\n':
                case '\r':
+                       vty->escape = VTY_CR;
+                       /* fallthru */
+               case '\n':
                        vty_out(vty, "\n");
                        buffer_flush_available(vty->obuf, vty->wfd);
                        vty_execute(vty);