Preventing duplicate field access

src/org/jetbrains/java/decompiler/modules/decompiler/SimplifyExprentsHelper.java

@@ -178,7 +178,7 @@ public class SimplifyExprentsHelper {
       }
 
       // expr++ and expr--
-      if (isIPPorIMM(current, next)) {
+      if (isIPPorIMM(current, next) || isIPPorIMM2(current, next)) {
         list.remove(index + 1);
         res = true;
         continue;
@@ -458,6 +458,48 @@ public class SimplifyExprentsHelper {
     return false;
   }
 
+  private static boolean isIPPorIMM2(Exprent first, Exprent second) {
+
+    if (first.type != Exprent.EXPRENT_ASSIGNMENT || second.type != Exprent.EXPRENT_ASSIGNMENT) {
+      return false;
+    }
+      
+    AssignmentExprent af = (AssignmentExprent)first;
+    AssignmentExprent as = (AssignmentExprent)second;
+    
+    if(as.getRight().type != Exprent.EXPRENT_FUNCTION) {
+      return false;
+    }
+    
+    FunctionExprent func = (FunctionExprent)as.getRight();
+    
+    if(func.getFuncType() != FunctionExprent.FUNCTION_ADD && func.getFuncType() != FunctionExprent.FUNCTION_SUB) {
+      return false;
+    }
+
+    Exprent econd = func.getLstOperands().get(0);
+    Exprent econst = func.getLstOperands().get(1);
+
+    if(econst.type != Exprent.EXPRENT_CONST && econd.type == Exprent.EXPRENT_CONST && func.getFuncType() == FunctionExprent.FUNCTION_ADD) {
+      econd = econst;
+      econst = func.getLstOperands().get(0);
+    }
+
+    if(econst.type == Exprent.EXPRENT_CONST && ((ConstExprent)econst).hasValueOne()) {
+      if(af.getLeft().equals(econd) && af.getRight().equals(as.getLeft()) && (af.getLeft().getExprentUse() & Exprent.MULTIPLE_USES) != 0) {
+        int type = func.getFuncType() == FunctionExprent.FUNCTION_ADD ? FunctionExprent.FUNCTION_IPP : FunctionExprent.FUNCTION_IMM;
+        
+        FunctionExprent ret = new FunctionExprent(type, af.getRight(), func.bytecode);
+        ret.setImplicitType(VarType.VARTYPE_INT);
+        
+        af.setRight(ret);
+        return true;
+      }
+    }
+    
+    return false;
+  }
+  
   private static boolean isMonitorExit(Exprent first) {
     if (first.type == Exprent.EXPRENT_MONITOR) {
       MonitorExprent expr = (MonitorExprent)first;

src/org/jetbrains/java/decompiler/modules/decompiler/decompose/DominatorTreeExceptionFilter.java

@@ -134,8 +134,9 @@ public class DominatorTreeExceptionFilter {
               exit = childid;
             }
             else {
-              // exit = map.containsKey(handler)?-1:mapChild.get(handler); FIXME: Eclipse bug?
-              exit = map.containsKey(handler) ? -1 : mapChild.get(handler);
+              // after replacing 'new Integer(-1)' with '-1' Eclipse throws a NullPointerException on the following line
+              // could be a bug in Eclipse or some obscure specification glitch, FIXME: needs further investigation
+              exit = map.containsKey(handler) ? new Integer(-1) : mapChild.get(handler);
             }
 
             if (exit != null) {

src/org/jetbrains/java/decompiler/modules/decompiler/exps/FieldExprent.java

@@ -54,7 +54,7 @@ public class FieldExprent extends Exprent {
 
   @Override
   public int getExprentUse() {
-    return instance == null ? Exprent.MULTIPLE_USES : instance.getExprentUse() & Exprent.MULTIPLE_USES;
+    return 0; // multiple references to a field considered dangerous in a multithreaded environment, thus no Exprent.MULTIPLE_USES set here
   }
 
   @Override