Use canonical index name when dropping

Should fix loopbackio#354

Author: jlawrencecfm

lib/migration.js

@@ -744,6 +744,7 @@ function mixinMigration(PostgreSQL) {
 
     // remove indexes
     aiNames.forEach(function(indexName) {
+      var schema = self.escapeName(self.schema(model) || 'public');
       var i = ai[indexName];
       var propName = propNameRegEx.exec(indexName);
       var si; // index definition from model schema
@@ -753,7 +754,7 @@ function mixinMigration(PostgreSQL) {
       propName = propName && self.propertyName(model, propName[1]) || null;
       if (!(indexNames.indexOf(indexName) > -1) && !(propName && m.properties[propName] &&
       m.properties[propName].index)) {
-        sql.push('DROP INDEX ' + self.escapeName(indexName));
+        sql.push('DROP INDEX ' + schema + '.' + self.escapeName(indexName));
       } else {
         // The index was found, verify that database matches what we're expecting.
         // first: check single column indexes.
@@ -765,7 +766,7 @@ function mixinMigration(PostgreSQL) {
               !((!si.type || si.type === ai[indexName].type) && (!si.unique || si.unique === ai[indexName].unique))
             ) {
               // Drop the index if the type or unique differs from the actual table
-              sql.push('DROP INDEX ' + self.escapeName(indexName));
+              sql.push('DROP INDEX ' + schema + '.' + self.escapeName(indexName));
               delete ai[indexName];
             }
           }
@@ -791,7 +792,7 @@ function mixinMigration(PostgreSQL) {
           }
 
           if (!identical) {
-            sql.push('DROP INDEX ' + self.escapeName(indexName));
+            sql.push('DROP INDEX ' + schema + '.' + self.escapeName(indexName));
             delete ai[indexName];
           }
         }