From f15c5702f87bb10aa5d5aceff250dfa9d2e1b634 Mon Sep 17 00:00:00 2001
From: Alan Coopersmith <alan.coopersmith@oracle.com>
Date: Mon, 21 Apr 2025 14:30:36 -0700
Subject: [PATCH] mouse.c: handle -Wanalyzer-null-dereference in
 createProtoList
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Should never happen, but the compiler would need to understand the flow
of our state machine to realize that, and this protects us if that ever
changes.

Clears warning from gcc 14.2.0:
mouse.c: In function ‘createProtoList’:
mouse.c:3226:30: warning: dereference of NULL ‘protoList’ [CWE-476]
 [-Wanalyzer-null-dereference]
 3226 |         for (i = 0; protoList[i] != PROT_UNKNOWN; i++) {
      |                     ~~~~~~~~~^~~

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/driver/xf86-input-mouse/-/merge_requests/23>
---
 src/mouse.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/mouse.c b/src/mouse.c
index 438e8ba..b79e425 100644
--- a/src/mouse.c
+++ b/src/mouse.c
@@ -3215,6 +3215,11 @@ createProtoList(MouseDevPtr pMse, MouseProtocolID *protoList)
         AP_DBGC(("%2.2x ", (unsigned char) mPriv->data[i]));
     AP_DBGC(("\n"));
 
+    if (protoList == NULL) {
+        AP_DBG(("Skipping probe, protoList is NULL"));
+        return;
+    }
+
 #if HAVE_THREADED_INPUT
     input_lock();
 #else