fixing interpreting multiple WPIMULT records

During a report step, if there are multple records for a well has
defaulted connection and completion information, only the last record
will apply to that well.

But the following record is considered not to have defaulted connection
and completion information.

WMPIMUL
  'WEL' 0.8 0 0 0 /
/

src/opm/input/eclipse/Schedule/KeywordHandlers.cpp

@@ -1774,11 +1774,58 @@ Well{0} entered with disallowed 'FIELD' parent group:
     }
 
     void Schedule::handleWPIMULT(HandlerContext& handlerContext) {
-        for (const auto& record : handlerContext.keyword) {
+        // from the third item to the seventh item in the WPIMULT record, they are numbers indicate
+        // the I, J, K location and completion number range.
+        // When defaulted, it assumes it is negative
+        // When inputting a negative value, it assumes it is defaulted.
+        auto defaultConCompRec = [] (const DeckRecord& rec)-> bool {
+            bool default_connections = true;
+            for (size_t i = 2;  i < rec.size(); ++i) {
+                const auto& item = rec.getItem(i);
+                if (item.get<int>(0) >= 0) {
+                    default_connections = false;
+                    break;
+                }
+            }
+            return default_connections;
+        };
+
+        auto lastRecordWithDefaultConnections = [&defaultConCompRec, this, &handlerContext] (const DeckKeyword& keyword) {
+            std::unordered_map<std::string, size_t> last_index_default_cons_comps;
+            for (size_t i = 0; i < keyword.size(); ++i) {
+                const auto& record = keyword.getRecord(i);
+                if (defaultConCompRec(record)) {
+                    const std::string& wellNamePattern = record.getItem("WELL").getTrimmedString(0);
+                    const auto& well_names = this->wellNames(wellNamePattern, handlerContext);
+
+                    for (const auto& wname : well_names) {
+                        last_index_default_cons_comps[wname] = i;
+                    }
+                }
+            }
+            return last_index_default_cons_comps;
+        };
+
+        const auto last_index_default_cons_comps = lastRecordWithDefaultConnections(handlerContext.keyword);
+
+        for (size_t i_rec = 0; i_rec < handlerContext.keyword.size(); ++i_rec) {
+            const auto& record = handlerContext.keyword.getRecord(i_rec);
+            // whether this record has defaulted connection and completion information
+            const bool default_con_comp = defaultConCompRec(record);
+
             const std::string& wellNamePattern = record.getItem("WELL").getTrimmedString(0);
             const auto& well_names = this->wellNames(wellNamePattern, handlerContext);
 
             for (const auto& wname : well_names) {
+                // for records with defaulted connection and completion information, we only use the last record for that well
+                if (default_con_comp) {
+                    const auto search = last_index_default_cons_comps.find(wname);
+                    if (search != last_index_default_cons_comps.end() && i_rec < search->second) {
+                        // it is not the last record with defaulted connection and completion information for that well
+                        // we skp this record for this well
+                        continue;
+                    }
+                }
                 auto well = this->snapshots.back().wells( wname );
                 if (well.handleWPIMULT(record))
                     this->snapshots.back().wells.update( std::move(well));

src/opm/input/eclipse/Schedule/Well/Well.cpp

@@ -61,7 +61,7 @@ namespace {
         if (item.defaultApplied(0))
             return true;
 
-        if (item.get<int>(0) == 0)
+        if (item.get<int>(0) <= 0)
             return true;
 
         return false;

src/opm/input/eclipse/share/keywords/000_Eclipse100/W/WPIMULT

@@ -15,23 +15,28 @@
     },
     {
       "name": "I",
-      "value_type": "INT"
+      "value_type": "INT",
+      "default" : -1
     },
     {
       "name": "J",
-      "value_type": "INT"
+      "value_type": "INT",
+      "default" : -1
     },
     {
       "name": "K",
-      "value_type": "INT"
+      "value_type": "INT",
+      "default" : -1
     },
     {
       "name": "FIRST",
-      "value_type": "INT"
+      "value_type": "INT",
+      "default" : -1
     },
     {
       "name": "LAST",
-      "value_type": "INT"
+      "value_type": "INT",
+      "default" : -1
     }
   ]
 }