[PATCH] xf86-input-synaptics: fix creation of repeater fifo

[Peter Hutterer]

On Sun, Sep 28, 2008 at 03:11:46PM +0100, Magnus Kessler wrote:
> Testing status against EEXIST is wrong and we should check errno instead if 
> we want to allow the use of an existing file. However, since we pass a file 
> name that in principle could be any existing file (not just fifos) is there 
> any guarantee that we can later actually use the fifo?

Thanks. There is no guarantee that we can use it, but at the same time the
use-case where the pipe already exists is common.
In the simple case of a server restart, the first mkfifo command succeeds but
the second fails with EEXIST. So the pipe is still there and should be used.
Admittedly, it might be a good idea to clean up after ourselves and delete the
fifo if we have created it in the first place. What about the (compile-tested)
code below?

Cheers,
  Peter

diff --git a/src/synaptics.c b/src/synaptics.c
index 18168e0..e5cb7f0 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -512,6 +512,9 @@ static void set_repeater_fifo(LocalDevicePtr local)
 	if (status && (errno != EEXIST)) {
 	    xf86Msg(X_ERROR, "%s can't create repeater fifo\n", local->name);
 	} else {
+            if (!status)
+                priv->fifo_path = strdup(repeater); /* for unlinking later */
+
 	    /* open the repeater fifo */
 	    optList = xf86NewOption("Device", repeater);
 	    if ((priv->fifofd = xf86OpenSerial(optList)) == -1) {
@@ -608,6 +611,7 @@ SynapticsPreInit(InputDriverPtr drv, IDevPtr dev, int flags)
     DBG(9, XisbTrace(priv->comm.buffer, 1));
 
     priv->fifofd = -1;
+    priv->fifo_path = NULL;
     set_repeater_fifo(local);
 
     if (!QueryHardware(local)) {
@@ -655,6 +659,13 @@ static void SynapticsUnInit(InputDriverPtr drv,
                             InputInfoPtr   local,
                             int            flags)
 {
+    SynapticsPrivate *priv = (SynapticsPrivate *) (local->private);
+
+    if (priv->fifo_path)
+    {
+        unlink(priv->fifo_path);
+        xfree(priv->fifo_path);
+    }
     xfree(local->private);
     local->private = NULL;
     xf86DeleteInput(local, 0);
diff --git a/src/synapticsstr.h b/src/synapticsstr.h
index e5202d1..d93e279 100644
--- a/src/synapticsstr.h
+++ b/src/synapticsstr.h
@@ -96,6 +96,7 @@ typedef struct _SynapticsPrivateRec
 
     struct CommData comm;
     int fifofd;		 		/* fd for fifo */
+    char *fifo_path;                    /* path to fifo for unlinking */
 
     SynapticsMoveHistRec move_hist[SYNAPTICS_MOVE_HISTORY]; /* movement history */
     int hist_index;			/* Last added entry in move_hist[] */