Index: src/com/iver/cit/gvsig/geoprocess/core/fmap/DefinitionUtils.java
===================================================================
--- src/com/iver/cit/gvsig/geoprocess/core/fmap/DefinitionUtils.java	(revision 39491)
+++ src/com/iver/cit/gvsig/geoprocess/core/fmap/DefinitionUtils.java	(working copy)
@@ -110,9 +110,12 @@
 		solution.setName(layer.getName());
 		solution.setShapeType(layer.getShapeType());
 		SelectableDataSource datasource = layer.getRecordset();
-		int numFields = datasource.getFieldCount();
-		FieldDescription[] fields =
-			new FieldDescription[numFields];
+		//int numFields = datasource.getFieldCount();
+		//FieldDescription[] fields =
+		//	new FieldDescription[numFields];
+		FieldDescription[] fieldsDescription = null;
+		fieldsDescription = datasource.getFieldsDescription();
+		/*
 		FieldDescription fieldDesc = null;
 		for(int i = 0; i < numFields; i++){
 			fieldDesc = new FieldDescription();
@@ -125,6 +128,8 @@
 			fields[i] = fieldDesc;
 		}
 		solution.setFieldsDesc(fields);
+		*/
+		solution.setFieldsDesc(fieldsDescription);
 		return solution;
 	}
 
Index: src/com/iver/cit/gvsig/geoprocess/impl/merge/fmap/MergeVisitor.java
===================================================================
--- src/com/iver/cit/gvsig/geoprocess/impl/merge/fmap/MergeVisitor.java	(revision 39491)
+++ src/com/iver/cit/gvsig/geoprocess/impl/merge/fmap/MergeVisitor.java	(working copy)
@@ -135,6 +135,19 @@
 					}else{
 						values[i] = recordset.getFieldValue(index, fieldIndex);
 					}
+					// afalciano: ...but also field length and precision
+					int fieldLength = fields[i].getFieldLength();
+					int fieldDecimalCount = fields[i].getFieldDecimalCount();
+					FieldDescription[] recordsetFieldsDescription = recordset.getFieldsDescription();
+					int recordsetLength = recordsetFieldsDescription[fieldIndex].getFieldLength();
+					int recordsetDecimalCount = recordsetFieldsDescription[fieldIndex].getFieldDecimalCount();
+					if(fieldLength != recordsetLength){
+						fields[i].setFieldLength(recordsetLength);
+					}
+					if(fieldDecimalCount != recordsetDecimalCount){
+						fields[i].setFieldDecimalCount(recordsetLength);
+					}
+					
 				}
 			} catch (ReadDriverException e) {
 				throw new ProcessVisitorException(recordset.getName(),e,"Error en merge al tratar de leer el atributo de un feature de una de las capas");