Attachment 127213 Details for Bug 98204 – Behavioral improvement

[patch] Behavioral improvement

Do-not-clobber-call-by-reference-variables-on-failure.patch (text/plain), 2.63 KB, created by j.witteveen on 2016-10-11 14:20:34 UTC

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Creator: j.witteveen

Created: 2016-10-11 14:20:34 UTC

Size: 2.63 KB

patch

obsolete

>From 10816eb91b413db99f1c3d38acf36f433c3eb49d Mon Sep 17 00:00:00 2001
>From: Jouke Witteveen <j.witteveen@gmail.com>
>Date: Tue, 11 Oct 2016 16:12:13 +0200
>Subject: [PATCH] Do not clobber call-by-reference variables on failure
>
>Only touch *ndevices once we are sure to not return NULL.
>---
> src/XListDev.c | 19 ++++++++++---------
> 1 file changed, 10 insertions(+), 9 deletions(-)
>
>diff --git a/src/XListDev.c b/src/XListDev.c
>index f850cd0..b3870e8 100644
>--- a/src/XListDev.c
>+++ b/src/XListDev.c
>@@ -184,7 +184,7 @@ XListInputDevices(
>     XAnyClassPtr Any;
>     char *end = NULL;
>     unsigned char *nptr, *Nptr;
>-    int i;
>+    int i, ndev;
>     unsigned long rlen;
>     XExtDisplayInfo *info = XInput_find_display(dpy);
> 
>@@ -202,8 +202,8 @@ XListInputDevices(
> 	return (XDeviceInfo *) NULL;
>     }
> 
>-    if ((*ndevices = rep.ndevices)) {	/* at least 1 input device */
>-	size = *ndevices * sizeof(XDeviceInfo);
>+    if ((ndev = rep.ndevices)) {	/* at least 1 input device */
>+	size = ndev * sizeof(XDeviceInfo);
> 	if (rep.length < (INT_MAX >> 2)) {
> 	    rlen = rep.length << 2;	/* multiply length by 4    */
> 	    slist = list = Xmalloc(rlen);
>@@ -216,10 +216,10 @@ XListInputDevices(
> 	}
> 	_XRead(dpy, (char *)list, rlen);
> 
>-	any = (xAnyClassPtr) ((char *)list + (*ndevices * sizeof(xDeviceInfo)));
>+	any = (xAnyClassPtr) ((char *)list + (ndev * sizeof(xDeviceInfo)));
> 	sav_any = any;
> 	end = (char *)list + rlen;
>-	for (i = 0; i < *ndevices; i++, list++) {
>+	for (i = 0; i < ndev; i++, list++) {
>             s = SizeClassInfo(&any, end - (char *)any, (int)list->num_classes);
>             if (!s)
>                 goto out;
>@@ -227,7 +227,7 @@ XListInputDevices(
> 	}
> 
> 	Nptr = ((unsigned char *)list) + rlen;
>-	for (i = 0, nptr = (unsigned char *)any; i < *ndevices; i++) {
>+	for (i = 0, nptr = (unsigned char *)any; i < ndev; i++) {
> 	    if (nptr >= Nptr)
> 		goto out;
> 	    size += *nptr + 1;
>@@ -242,11 +242,12 @@ XListInputDevices(
> 	    return (XDeviceInfo *) NULL;
> 	}
> 	sclist = clist;
>+	*ndevices = ndev;
> 	Any = (XAnyClassPtr) ((char *)clist +
>-			      (*ndevices * sizeof(XDeviceInfo)));
>+			      (ndev * sizeof(XDeviceInfo)));
> 	list = slist;
> 	any = sav_any;
>-	for (i = 0; i < *ndevices; i++, list++, clist++) {
>+	for (i = 0; i < ndev; i++, list++, clist++) {
> 	    clist->type = list->type;
> 	    clist->id = list->id;
> 	    clist->use = list->use;
>@@ -259,7 +260,7 @@ XListInputDevices(
> 	clist = sclist;
> 	nptr = (unsigned char *)any;
> 	Nptr = (unsigned char *)Any;
>-	for (i = 0; i < *ndevices; i++, clist++) {
>+	for (i = 0; i < ndev; i++, clist++) {
> 	    clist->name = (char *)Nptr;
> 	    memcpy(Nptr, nptr + 1, *nptr);
> 	    Nptr += (*nptr);
>-- 
>2.10.0
>

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