Coverity: omit tests

.github/workflows/coverity.yml

@@ -28,7 +28,7 @@ jobs:
         run: |
           mkdir build
           cd build
-          cmake -DCARES_BUILD_TESTS=ON -G Ninja ..
+          cmake -DCARES_BUILD_TESTS=OFF -G Ninja ..
       - name: Build with cov-build
         run: |
           export PATH=`pwd`/cov-analysis-linux64/bin:$PATH

src/lib/ares_update_servers.c

@@ -91,7 +91,7 @@ static ares_bool_t ares_ipv6_subnet_matches(const unsigned char  netbase[16],
   memset(mask, 0xFF, netmask / 8);
 
   /* Set remaining bits */
-  if (netmask % 8) {
+  if (netmask % 8 && netmask < 128 /* Silence coverity */) {
     mask[netmask / 8] = (unsigned char)(0xff << (8 - (netmask % 8)));
   }