From d8bb8ed5bf7e7b7f2b9606b6afc4890e88c639e9 Mon Sep 17 00:00:00 2001
From: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Date: Tue, 30 May 2017 23:26:10 +0200
Subject: [PATCH] proc/variables: fill Len field of maps when recursion limit
 is reached (#834)

If we don't fill the Len field there will be no way for the user to
distinguish maps we didn't load from empty maps.
---
 _fixtures/testvariables2.go    | 8 +++++++-
 pkg/proc/variables.go          | 3 +++
 service/test/variables_test.go | 1 +
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/_fixtures/testvariables2.go b/_fixtures/testvariables2.go
index a928ec55..e6ef5e1a 100644
--- a/_fixtures/testvariables2.go
+++ b/_fixtures/testvariables2.go
@@ -85,6 +85,10 @@ type Item struct {
 
 type Menu []Item
 
+type truncatedMap struct {
+	v []map[string]astruct
+}
+
 func main() {
 	i1 := 1
 	i2 := 2
@@ -223,6 +227,8 @@ func main() {
 	zsvar := struct{}{}
 	zsslice := make([]struct{}, 3)
 	zsvmap := map[string]struct{}{"testkey": struct{}{}}
+	var tm truncatedMap
+	tm.v = []map[string]astruct{m1}
 
 	var amb1 = 1
 	runtime.Breakpoint()
@@ -231,5 +237,5 @@ func main() {
 	}
 
 	runtime.Breakpoint()
-	fmt.Println(i1, i2, i3, p1, amb1, s1, s3, a1, p2, p3, s2, as1, str1, f1, fn1, fn2, nilslice, nilptr, ch1, chnil, m1, mnil, m2, m3, up1, i4, i5, i6, err1, err2, errnil, iface1, iface2, ifacenil, arr1, parr, cpx1, const1, iface3, iface4, recursive1, recursive1.x, iface5, iface2fn1, iface2fn2, bencharr, benchparr, mapinf, mainMenu, b, b2, sd, anonstruct1, anonstruct2, anoniface1, anonfunc, mapanonstruct1, ifacearr, efacearr, ni8, ni16, ni32, pinf, ninf, nan, zsvmap, zsslice, zsvar)
+	fmt.Println(i1, i2, i3, p1, amb1, s1, s3, a1, p2, p3, s2, as1, str1, f1, fn1, fn2, nilslice, nilptr, ch1, chnil, m1, mnil, m2, m3, up1, i4, i5, i6, err1, err2, errnil, iface1, iface2, ifacenil, arr1, parr, cpx1, const1, iface3, iface4, recursive1, recursive1.x, iface5, iface2fn1, iface2fn2, bencharr, benchparr, mapinf, mainMenu, b, b2, sd, anonstruct1, anonstruct2, anoniface1, anonfunc, mapanonstruct1, ifacearr, efacearr, ni8, ni16, ni32, pinf, ninf, nan, zsvmap, zsslice, zsvar, tm)
 }
diff --git a/pkg/proc/variables.go b/pkg/proc/variables.go
index 59bcfeb2..6101bcfc 100644
--- a/pkg/proc/variables.go
+++ b/pkg/proc/variables.go
@@ -824,6 +824,9 @@ func (v *Variable) loadValueInternal(recurseLevel int, cfg LoadConfig) {
 	case reflect.Map:
 		if recurseLevel <= cfg.MaxVariableRecurse {
 			v.loadMap(recurseLevel, cfg)
+		} else {
+			// loads length so that the client knows that the map isn't empty
+			v.mapIterator()
 		}
 
 	case reflect.String:
diff --git a/service/test/variables_test.go b/service/test/variables_test.go
index 61923623..5e9a897c 100644
--- a/service/test/variables_test.go
+++ b/service/test/variables_test.go
@@ -694,6 +694,7 @@ func TestEvalExpression(t *testing.T) {
 
 		{"zsslice", false, `[]struct {} len: 3, cap: 3, [{},{},{}]`, `[]struct {} len: 3, cap: 3, [...]`, "[]struct {}", nil},
 		{"zsvmap", false, `map[string]struct {} ["testkey": {}, ]`, `map[string]struct {} [...]`, "map[string]struct {}", nil},
+		{"tm", false, "main.truncatedMap {v: []map[string]main.astruct len: 1, cap: 1, [[...]]}", "main.truncatedMap {v: []map[string]main.astruct len: 1, cap: 1, [...]}", "main.truncatedMap", nil},
 	}
 
 	ver, _ := proc.ParseVersionString(runtime.Version())