configure: use pcap-config --static-pcap-only if available.

If we're linking with a libpcap in ../libpcap*, it's static, but we only
need to link with the libraries on wich it immediately depends, we don't
need to link with the libraries on which those libraries depend, etc..

So, if ../libpcap*/pcap-config supports --static-pcap-only, use that.

aclocal.m4

@@ -735,8 +735,44 @@ AC_DEFUN(AC_LBL_LIBPCAP,
             # routines in those libraries, so we'll need to link with
             # them, because we'll be linking statically with it.
             #
+            # If it supports --static-pcap-only. use that, as we will be
+            # linking with a static libpcap but won't be linking
+            # statically with any of the libraries on which it depends;
+            # those libraries might not even have static versions
+            # installed.
+            #
+            # That means we need to find out the libraries on which
+            # libpcap directly depends, so we can link with them, but we
+            # don't need to link with the libraries on which those
+            # libraries depend as, on all UN*Xes with which I'm
+            # familiar, the libraries on which a shared library depends
+            # are stored in the library and are automatically loaded by
+            # the run-time linker, without the executable having to be
+            # linked with those libraries.  (This allows a library to be
+            # changed to depend on more libraries without breaking that
+            # library's ABI.)
+            #
+            # The only way to test for that support is to see if the
+            # script contains the string "static-pcap-only"; we can't
+            # try using that flag and checking for errors, as the
+            # versions of the script that didn't have that flag wouldn't
+            # report or return an error for an unsupported command-line
+            # flag.  Those older versions provided, with --static, only
+            # the libraries on which libpcap depends, not the
+            # dependencies of those libraries; the versions with
+            # --static-pcap-only provide all the dependencies with
+            # --static, for the benefit of programs that are completely
+            # statically linked, and provide only the direct
+            # dependencies with --static-pcap-only.
+            #
+            if grep -s -q "static-pcap-only" "$PCAP_CONFIG"
+            then
+                static_opt="--static-pcap-only"
+            else
+                static_opt="--static"
+            fi
             $2="-I$local_pcap_dir $$2"
-            additional_libs=`"$PCAP_CONFIG" --static --additional-libs`
+            additional_libs=`"$PCAP_CONFIG" $static_opt --additional-libs`
             libpcap="$libpcap $additional_libs"
         else
             #

configure

@@ -5960,8 +5960,44 @@ fi
             # routines in those libraries, so we'll need to link with
             # them, because we'll be linking statically with it.
             #
+            # If it supports --static-pcap-only. use that, as we will be
+            # linking with a static libpcap but won't be linking
+            # statically with any of the libraries on which it depends;
+            # those libraries might not even have static versions
+            # installed.
+            #
+            # That means we need to find out the libraries on which
+            # libpcap directly depends, so we can link with them, but we
+            # don't need to link with the libraries on which those
+            # libraries depend as, on all UN*Xes with which I'm
+            # familiar, the libraries on which a shared library depends
+            # are stored in the library and are automatically loaded by
+            # the run-time linker, without the executable having to be
+            # linked with those libraries.  (This allows a library to be
+            # changed to depend on more libraries without breaking that
+            # library's ABI.)
+            #
+            # The only way to test for that support is to see if the
+            # script contains the string "static-pcap-only"; we can't
+            # try using that flag and checking for errors, as the
+            # versions of the script that didn't have that flag wouldn't
+            # report or return an error for an unsupported command-line
+            # flag.  Those older versions provided, with --static, only
+            # the libraries on which libpcap depends, not the
+            # dependencies of those libraries; the versions with
+            # --static-pcap-only provide all the dependencies with
+            # --static, for the benefit of programs that are completely
+            # statically linked, and provide only the direct
+            # dependencies with --static-pcap-only.
+            #
+            if grep -s -q "static-pcap-only" "$PCAP_CONFIG"
+            then
+                static_opt="--static-pcap-only"
+            else
+                static_opt="--static"
+            fi
             V_INCLS="-I$local_pcap_dir $V_INCLS"
-            additional_libs=`"$PCAP_CONFIG" --static --additional-libs`
+            additional_libs=`"$PCAP_CONFIG" $static_opt --additional-libs`
             libpcap="$libpcap $additional_libs"
         else
             #