check for missing Current instance in EachMap

NoEach and Each list both have this check, but it was missing in
EachMap. Refactor the EachList check to remove a level of indentation,
and make the check consistently near the start of the block.

terraform/evaluate.go

@@ -648,12 +648,18 @@ func (d *evaluationStateData) getResourceInstancesAll(addr addrs.Resource, rng t
 		for i := 0; i < length; i++ {
 			ty := schema.ImpliedType()
 			key := addrs.IntKey(i)
-			is, exists := rs.Instances[key]
+			is := rs.Instances[key]
-			if exists && is.Current != nil {
+			if is == nil || is.Current == nil {
+				// There shouldn't normally be "gaps" in our list but we'll
+				// allow it under the assumption that we're in a weird situation
+				// where e.g. someone has run "terraform state mv" to reorder
+				// a list and left a hole behind.
+				vals[i] = cty.UnknownVal(schema.ImpliedType())
+				continue
+			}
+
 			instAddr := addr.Instance(key).Absolute(d.ModulePath)
 
-				// Prefer pending value in plan if present. See getResourceInstanceSingle
-				// comment for the rationale.
 			if is.Current.Status == states.ObjectPlanned {
 				if change := d.Evaluator.Changes.GetResourceInstanceChange(instAddr, states.CurrentGen); change != nil {
 					val, err := change.After.Decode(ty)
@@ -695,13 +701,6 @@ func (d *evaluationStateData) getResourceInstancesAll(addr addrs.Resource, rng t
 				continue
 			}
 			vals[i] = ios.Value
-			} else {
-				// There shouldn't normally be "gaps" in our list but we'll
-				// allow it under the assumption that we're in a weird situation
-				// where e.g. someone has run "terraform state mv" to reorder
-				// a list and left a hole behind.
-				vals[i] = cty.UnknownVal(schema.ImpliedType())
-			}
 		}
 
 		// We use a tuple rather than a list here because resource schemas may
@@ -715,12 +714,14 @@ func (d *evaluationStateData) getResourceInstancesAll(addr addrs.Resource, rng t
 		vals := make(map[string]cty.Value, len(rs.Instances))
 		for k, is := range rs.Instances {
 			if sk, ok := k.(addrs.StringKey); ok {
+				if is == nil || is.Current == nil {
+					// Assume we're dealing with an instance that hasn't been created yet.
+					vals[string(sk)] = cty.UnknownVal(schema.ImpliedType())
+					continue
+				}
+
 				instAddr := addr.Instance(k).Absolute(d.ModulePath)
 
-				// Prefer pending value in plan if present. See getResourceInstanceSingle
-				// comment for the rationale.
-				// Prefer pending value in plan if present. See getResourceInstanceSingle
-				// comment for the rationale.
 				if is.Current.Status == states.ObjectPlanned {
 					if change := d.Evaluator.Changes.GetResourceInstanceChange(instAddr, states.CurrentGen); change != nil {
 						val, err := change.After.Decode(ty)