Don't narrow -i to one IP version when -i4 or -i6 follows it

Makefile.am

@@ -155,6 +155,7 @@ LINUX_TESTS = lib/dialects/linux/tests/case-10-mqueue.bash \
 	lib/dialects/linux/tests/case-20-inet6-ffffffff-handling.bash \
 	lib/dialects/linux/tests/case-20-inet6-socket-endpoint.bash \
 	lib/dialects/linux/tests/case-20-inet-socket-endpoint.bash \
+	lib/dialects/linux/tests/case-20-inet-version-after-all.bash \
 	lib/dialects/linux/tests/case-20-mmap.bash \
 	lib/dialects/linux/tests/case-20-udp-socket-state.bash \
 	lib/dialects/linux/tests/case-20-udp-state-filter.bash \

lib/dialects/linux/tests/case-20-inet-version-after-all.bash

@@ -0,0 +1,30 @@
+#!/bin/bash
+source tests/common.bash
+
+if [ -z "$(nc -h 2>&1 | grep '\s-6')" ]; then
+    echo "nc does not support -6 option, skipping" >> $report
+    exit 77
+fi
+
+# -i selects every IP version, so a following -i4 must not drop IPv6 files.
+nc -l -6 ::1 10002 > /dev/null < /dev/zero 2>> $report &
+server=$!
+sleep 1
+
+if ! kill -0 $server 2>/dev/null; then
+    echo "Maybe ipv6 stack is not available on this system, skipping" >> $report
+    exit 77
+fi
+
+fserver=/tmp/${name}-server-$$
+$lsof -n -P -p $server -a -i -i4 > $fserver
+kill -9 $server 2> /dev/null > /dev/null
+if ! grep -q "IPv6 .*TCP \[::1\]:10002 (LISTEN)" $fserver; then
+    echo "IPv6 socket missing with -i -i4" >> $report
+    cat $fserver >> $report
+    rm -f $fserver
+    exit 1
+fi
+
+rm -f $fserver
+exit 0

src/arg.c

@@ -1265,13 +1265,13 @@ int enter_network_address(struct lsof_context *ctx, /* context */
             if (!Fnet) {
                 Fnet = 1;
                 FnetTy = ft;
-            } else {
-                if (FnetTy) {
-                    if (FnetTy != ft)
-                        FnetTy = 0;
-                } else
-                    FnetTy = ft;
+            } else if (FnetTy && FnetTy != ft) {
+                FnetTy = 0;
             }
+            /*
+             * Otherwise all IP versions (a previous -i) or this one are
+             * already selected.
+             */
             return (0);
         }
     } else if (Fnet)