add a --with-system-java-websocket

there was a system Java-WebSocket in Fedora 35, f.e. but unaware
if this is actively packaged standalone in contemporary distros,
but useful for the coverity build case.

Change-Id: Id6393dbfb1c449b75391752a8bb5e5ea4481a084
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/173725
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>

RepositoryExternal.mk

@@ -3967,7 +3967,15 @@ endef
 
 endif # SYSTEM_JFREEREPORT
 
-# no known distro packaged Java-Websocket at present
+# As a guide, Java-Websocket was packaged for Fedora 35
+# https://src.fedoraproject.org/rpms/Java-WebSocket/tree/f35
+ifneq ($(SYSTEM_JAVA_WEBSOCKET),)
+
+define gb_Jar__use_java_websocket
+$(call gb_Jar_use_system_jar,$(1),$(JAVA_WEBSOCKET_JAR))
+endef
+
+else # !SYSTEM_JAVA_WEBSOCKET
 
 ifeq ($(ENABLE_JAVA),TRUE)
 $(eval $(call gb_Helper_register_jars_for_install,URE,ure, \
@@ -3979,6 +3987,8 @@ define gb_Jar__use_java_websocket
 $(call gb_Jar_use_jar,$(1),java_websocket)
 endef
 
+endif # SYSTEM_JAVA_WEBSOCKET
+
 # Executables
 
 define gb_Executable__register_bestreversemap

config_host.mk.in

@@ -386,6 +386,7 @@ export KF5_LIBS=$(gb_SPACE)@KF5_LIBS@
 export KF6_CFLAGS=$(gb_SPACE)@KF6_CFLAGS@
 export KF6_LIBS=$(gb_SPACE)@KF6_LIBS@
 export KRB5_LIBS=@KRB5_LIBS@
+export JAVA_WEBSOCKET_JAR=@JAVA_WEBSOCKET_JAR@
 export LCMS2_CFLAGS=$(gb_SPACE)@LCMS2_CFLAGS@
 export LCMS2_LIBS=$(gb_SPACE)@LCMS2_LIBS@
 export LD=@LD@
@@ -677,6 +678,7 @@ SYSTEM_EBOOK=@SYSTEM_EBOOK@
 SYSTEM_ETONYEK=@SYSTEM_ETONYEK@
 SYSTEM_EPUBGEN=@SYSTEM_EPUBGEN@
 SYSTEM_FREEHAND=@SYSTEM_FREEHAND@
+SYSTEM_JAVA_WEBSOCKET=@SYSTEM_JAVA_WEBSOCKET@
 SYSTEM_LIBATOMIC_OPS=@SYSTEM_LIBATOMIC_OPS@
 SYSTEM_LIBEOT=@SYSTEM_LIBEOT@
 SYSTEM_LIBEXTTEXTCAT=@SYSTEM_LIBEXTTEXTCAT@

configure.ac

@@ -13155,17 +13155,47 @@ AC_SUBST(LIBASSUAN_LIBS)
 AC_SUBST(GPGMEPP_CFLAGS)
 AC_SUBST(GPGMEPP_LIBS)
 
+AC_ARG_WITH(system-java-websocket,
+    AS_HELP_STRING([--with-system-java-websocket],
+        [Use Java-WebSocket already on system.]),,
+    [with_system_java_websocket="$with_system_jars"])
+
+AC_ARG_WITH(java-websocket-jar,
+    AS_HELP_STRING([--with-java-websocket-jar=JARFILE],
+        [Specify path to jarfile manually.]),
+    JAVA_WEBSOCKET_JAR=$withval)
+
 AC_MSG_CHECKING([whether to build Java Websocket for the UNO remote websocket client])
 if test "$with_java" != "no"; then
     AC_MSG_RESULT([yes])
     ENABLE_JAVA_WEBSOCKET=TRUE
-    BUILD_TYPE="$BUILD_TYPE JAVA_WEBSOCKET"
-    NEED_ANT=TRUE
+
+    dnl ===================================================================
+    dnl Check for system Java-WebSocket
+    dnl ===================================================================
+    AC_MSG_CHECKING([which Java-WebSocket to use])
+    if test "$with_system_java_websocket" = "yes"; then
+        AC_MSG_RESULT([external])
+        SYSTEM_JAVA_WEBSOCKET=TRUE
+        if test -z $JAVA_WEBSOCKET_JAR; then
+            JAVA_WEBSOCKET_JAR=/usr/share/java/Java-WebSocket/Java-WebSocket.jar
+        fi
+        if ! test -f $JAVA_WEBSOCKET_JAR; then
+            AC_MSG_ERROR(Java-WebSocket.jar not found.)
+        fi
+    else
+        AC_MSG_RESULT([internal])
+        SYSTEM_JAVA_WEBSOCKET=
+        BUILD_TYPE="$BUILD_TYPE JAVA_WEBSOCKET"
+        NEED_ANT=TRUE
+    fi
 else
     AC_MSG_RESULT([no])
     ENABLE_JAVA_WEBSOCKET=
 fi
 AC_SUBST(ENABLE_JAVA_WEBSOCKET)
+AC_SUBST(SYSTEM_JAVA_WEBSOCKET)
+AC_SUBST(JAVA_WEBSOCKET_JAR)
 
 AC_MSG_CHECKING([whether to build the Wiki Publisher extension])
 if test "x$enable_ext_wiki_publisher" = "xyes" -a "x$enable_extension_integration" != "xno" -a "$with_java" != "no"; then

distro-configs/LibreOfficeCoverity.conf

@@ -29,5 +29,7 @@
 --with-hsqldb-jar=/home/coverity/hsqldb.jar
 --with-system-rhino
 --with-rhino-jar=/home/coverity/js.jar
+--with-system-java-websocket
+--with-java-websocket-jar=/home/coverity/Java-WebSocket.jar
 --with-system-lockfile
 --enable-odk