dnsdist: Fix Coverity warning 445614: " Argument cannot be negative"

diff --git a/pdns/dnsdistdist/dnsdist-cache.cc b/pdns/dnsdistdist/dnsdist-cache.cc
index 841e37a442271838b238259c9affc642e8cc9e7b..e3522a38e8077bf0e648e4ed5cb87cdce74b0ed9 100644 (file)
--- a/pdns/dnsdistdist/dnsdist-cache.cc
+++ b/pdns/dnsdistdist/dnsdist-cache.cc
@@ -484,7 +484,11 @@ uint64_t DNSDistPacketCache::getEntriesCount()
 
 uint64_t DNSDistPacketCache::dump(int fileDesc, bool rawResponse)
 {
-  auto filePtr = pdns::UniqueFilePtr(fdopen(dup(fileDesc), "w"));
+  auto fileDescDuplicated = dup(fileDesc);
+  if (fileDescDuplicated < 0) {
+    return 0;
+  }
+  auto filePtr = pdns::UniqueFilePtr(fdopen(fileDescDuplicated, "w"));
   if (filePtr == nullptr) {
     return 0;
   }