Don't panic on indexed int64 fields (#23)

* Stop all db instances after tests (go-mgo#462)

If all tests pass, the builds for mongo earlier than 2.6 are still failing.
Running a clean up fixes the issue.

* fixing int64 type failing when getting indexes and trying to type them

* requested changes relating to case statement and panic

* Update README.md to credit @mapete94.

* tests: ensure indexed int64 fields do not cause a panic in Indexes()

See:
* #23
* https://github.com/go-mgo/mgo/issues/475
* go-mgo#476

README.md

@@ -21,7 +21,8 @@ Further PR's (with tests) are welcome, but please maintain backwards compatibili
 * Improved multi-document transaction performance ([details](https://github.com/globalsign/mgo/pull/10), [more](https://github.com/globalsign/mgo/pull/11), [more](https://github.com/globalsign/mgo/pull/16))
 * Fixes cursor timeouts ([details](https://jira.mongodb.org/browse/SERVER-24899))
 * Support index hints and timeouts for count queries ([details](https://github.com/globalsign/mgo/pull/17))
-* Allow dropping all indexes on a collection ([details](https://github.com/globalsign/mgo/pull/25))
+* Don't panic when handling indexed `int64` fields ([detials](https://github.com/go-mgo/mgo/issues/475))
+* Supports dropping all indexes on a collection ([details](https://github.com/globalsign/mgo/pull/25))
 * Annotates log entries/profiler output with optional appName on 3.4+ ([details](https://github.com/globalsign/mgo/pull/28))
 * Support for read-only [views](https://docs.mongodb.com/manual/core/views/) in 3.4+ ([details](https://github.com/globalsign/mgo/pull/33))
 
@@ -36,6 +37,7 @@ Further PR's (with tests) are welcome, but please maintain backwards compatibili
 * @feliixx
 * @fmpwizard
 * @jameinel
+* @mapete94
 * @Reenjii
 * @smoya
 * @wgallagher

session.go

@@ -1659,12 +1659,25 @@ func (idxs indexSlice) Swap(i, j int)      { idxs[i], idxs[j] = idxs[j], idxs[i]
 
 func simpleIndexKey(realKey bson.D) (key []string) {
 	for i := range realKey {
+		var vi int
 		field := realKey[i].Name
-		vi, ok := realKey[i].Value.(int)
-		if !ok {
+
+		switch realKey[i].Value.(type) {
+		case int64:
+			vf, _ := realKey[i].Value.(int64)
+			vi = int(vf)
+		case float64:
 			vf, _ := realKey[i].Value.(float64)
 			vi = int(vf)
+		case string:
+			if vs, ok := realKey[i].Value.(string); ok {
+				key = append(key, "$"+vs+":"+field)
+				continue
+			}
+		case int:
+			vi = realKey[i].Value.(int)
 		}
+
 		if vi == 1 {
 			key = append(key, field)
 			continue
@@ -1673,10 +1686,6 @@ func simpleIndexKey(realKey bson.D) (key []string) {
 			key = append(key, "-"+field)
 			continue
 		}
-		if vs, ok := realKey[i].Value.(string); ok {
-			key = append(key, "$"+vs+":"+field)
-			continue
-		}
 		panic("Got unknown index key type for field " + field)
 	}
 	return

session_internal_test.go

@@ -0,0 +1,24 @@
+package mgo
+
+import (
+	"testing"
+
+	"github.com/globalsign/mgo/bson"
+)
+
+// This file is for testing functions that are not exported outside the mgo
+// package - avoid doing so if at all possible.
+
+// Ensures indexed int64 fields do not cause mgo to panic.
+//
+// See https://github.com/globalsign/mgo/pull/23
+func TestIndexedInt64FieldsBug(t *testing.T) {
+	input := bson.D{
+		{Name: "testkey", Value: int(1)},
+		{Name: "testkey", Value: int64(1)},
+		{Name: "testkey", Value: "test"},
+		{Name: "testkey", Value: float64(1)},
+	}
+
+	_ = simpleIndexKey(input)
+}