src/share/classes/com/sun/tools/javac/comp/Flow.java

*** 379,389 ****
       */
      void letInit(DiagnosticPosition pos, VarSymbol sym) {
          if (sym.adr >= firstadr && trackable(sym)) {
              if ((sym.flags() & FINAL) != 0) {
                  if ((sym.flags() & PARAMETER) != 0) {
!                     if ((sym.flags() & DISJUNCTION) != 0) { //multi-catch parameter
                          log.error(pos, "multicatch.parameter.may.not.be.assigned",
                                    sym);
                      }
                      else {
                          log.error(pos, "final.parameter.may.not.be.assigned",
--- 379,389 ----
       */
      void letInit(DiagnosticPosition pos, VarSymbol sym) {
          if (sym.adr >= firstadr && trackable(sym)) {
              if ((sym.flags() & FINAL) != 0) {
                  if ((sym.flags() & PARAMETER) != 0) {
!                     if ((sym.flags() & UNION) != 0) { //multi-catch parameter
                          log.error(pos, "multicatch.parameter.may.not.be.assigned",
                                    sym);
                      }
                      else {
                          log.error(pos, "final.parameter.may.not.be.assigned",
*** 1001,1011 ****
          List<Type> caughtPrev = caught;
          List<Type> thrownPrev = thrown;
          thrown = List.nil();
          for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
              List<JCExpression> subClauses = TreeInfo.isMultiCatch(l.head) ?
!                     ((JCTypeDisjunction)l.head.param.vartype).alternatives :
                      List.of(l.head.param.vartype);
              for (JCExpression ct : subClauses) {
                  caught = chk.incl(ct.type, caught);
              }
          }
--- 1001,1011 ----
          List<Type> caughtPrev = caught;
          List<Type> thrownPrev = thrown;
          thrown = List.nil();
          for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
              List<JCExpression> subClauses = TreeInfo.isMultiCatch(l.head) ?
!                     ((JCTypeUnion)l.head.param.vartype).alternatives :
                      List.of(l.head.param.vartype);
              for (JCExpression ct : subClauses) {
                  caught = chk.incl(ct.type, caught);
              }
          }
*** 1073,1083 ****
          List<Type> caughtInTry = List.nil();
          for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
              alive = true;
              JCVariableDecl param = l.head.param;
              List<JCExpression> subClauses = TreeInfo.isMultiCatch(l.head) ?
!                     ((JCTypeDisjunction)l.head.param.vartype).alternatives :
                      List.of(l.head.param.vartype);
              List<Type> ctypes = List.nil();
              List<Type> rethrownTypes = chk.diff(thrownInTry, caughtInTry);
              for (JCExpression ct : subClauses) {
                  Type exc = ct.type;
--- 1073,1083 ----
          List<Type> caughtInTry = List.nil();
          for (List<JCCatch> l = tree.catchers; l.nonEmpty(); l = l.tail) {
              alive = true;
              JCVariableDecl param = l.head.param;
              List<JCExpression> subClauses = TreeInfo.isMultiCatch(l.head) ?
!                     ((JCTypeUnion)l.head.param.vartype).alternatives :
                      List.of(l.head.param.vartype);
              List<Type> ctypes = List.nil();
              List<Type> rethrownTypes = chk.diff(thrownInTry, caughtInTry);
              for (JCExpression ct : subClauses) {
                  Type exc = ct.type;