database/sql: fix conversions to and from user-defined types

In particular, don't assume that one reflect.Value can be assigned to another just because they have the same reflect.Kind.

Fixes #12401

Change-Id: Ia4605a5c46557ff8f8f1d44f26d492850666c6d1
Reviewed-on: https://go-review.googlesource.com/15420
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/database/sql/convert.go b/src/database/sql/convert.go
index c0b38a24940fcade4452df0b5cdae6369420d3df..bba5a8843a0fcf9b2e6b3fc69589c58499bcedc4 100644 (file)
--- a/src/database/sql/convert.go
+++ b/src/database/sql/convert.go
@@ -203,11 +203,16 @@ func convertAssign(dest, src interface{}) error {
        }
 
        dv := reflect.Indirect(dpv)
-       if dv.Kind() == sv.Kind() {
+       if sv.IsValid() && sv.Type().AssignableTo(dv.Type()) {
                dv.Set(sv)
                return nil
        }
 
+       if dv.Kind() == sv.Kind() && sv.Type().ConvertibleTo(dv.Type()) {
+               dv.Set(sv.Convert(dv.Type()))
+               return nil
+       }
+
        switch dv.Kind() {
        case reflect.Ptr:
                if src == nil {

diff --git a/src/database/sql/convert_test.go b/src/database/sql/convert_test.go
index 98af9fb64c58ba39dcadfe9ae2b1e7e6eeb37ea1..1fab282b40896ab816d1ceb12a9b855d6a887a9b 100644 (file)
--- a/src/database/sql/convert_test.go
+++ b/src/database/sql/convert_test.go
@@ -16,23 +16,28 @@ import (
 var someTime = time.Unix(123, 0)
 var answer int64 = 42
 
+type userDefined float64
+
+type userDefinedSlice []int
+
 type conversionTest struct {
        s, d interface{} // source and destination
 
        // following are used if they're non-zero
-       wantint   int64
-       wantuint  uint64
-       wantstr   string
-       wantbytes []byte
-       wantraw   RawBytes
-       wantf32   float32
-       wantf64   float64
-       wanttime  time.Time
-       wantbool  bool // used if d is of type *bool
-       wanterr   string
-       wantiface interface{}
-       wantptr   *int64 // if non-nil, *d's pointed value must be equal to *wantptr
-       wantnil   bool   // if true, *d must be *int64(nil)
+       wantint    int64
+       wantuint   uint64
+       wantstr    string
+       wantbytes  []byte
+       wantraw    RawBytes
+       wantf32    float32
+       wantf64    float64
+       wanttime   time.Time
+       wantbool   bool // used if d is of type *bool
+       wanterr    string
+       wantiface  interface{}
+       wantptr    *int64 // if non-nil, *d's pointed value must be equal to *wantptr
+       wantnil    bool   // if true, *d must be *int64(nil)
+       wantusrdef userDefined
 }
 
 // Target variables for scanning into.
@@ -145,6 +150,12 @@ var conversionTests = []conversionTest{
        {s: true, d: &scaniface, wantiface: true},
        {s: nil, d: &scaniface},
        {s: []byte(nil), d: &scaniface, wantiface: []byte(nil)},
+
+       // To a user-defined type
+       {s: 1.5, d: new(userDefined), wantusrdef: 1.5},
+       {s: int64(123), d: new(userDefined), wantusrdef: 123},
+       {s: "1.5", d: new(userDefined), wantusrdef: 1.5},
+       {s: []byte{1, 2, 3}, d: new(userDefinedSlice), wanterr: `unsupported driver -> Scan pair: []uint8 -> *sql.userDefinedSlice`},
 }
 
 func intPtrValue(intptr interface{}) interface{} {
@@ -228,6 +239,9 @@ func TestConversions(t *testing.T) {
                                }
                        }
                }
+               if ct.wantusrdef != 0 && ct.wantusrdef != *ct.d.(*userDefined) {
+                       errf("want userDefined %f, got %f", ct.wantusrdef, *ct.d.(*userDefined))
+               }
        }
 }