From 2d6bc19ad7bb214c5803e5f457a3f34926610f7d Mon Sep 17 00:00:00 2001
From: Alessandro Arzilli <alessandro.arzilli@gmail.com>
Date: Wed, 3 Jun 2020 20:10:14 +0200
Subject: [PATCH] service/api: do not try to convert unreadable goroutines
 (#2070)

When reading truncated core files GoroutinesInfo will sometimes produce
some proc.G structs with only the Unreadable field set. These proc.G
can not be used for anything, but the service layer will still try to
convert them.
Since they are not fully initialized parts of the conversion will fail,
api.ConvertGoroutine should not try to call methods of unreadable
goroutines.

Fixes a bug reported on the mailing list.
https://groups.google.com/forum/#!msg/delve-dev/gauDqYaD81c/K5YDNBOhAAAJ
---
 service/api/conversions.go | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/service/api/conversions.go b/service/api/conversions.go
index 321b7a4e..c22035e1 100644
--- a/service/api/conversions.go
+++ b/service/api/conversions.go
@@ -257,7 +257,10 @@ func ConvertGoroutine(g *proc.G) *Goroutine {
 	if th != nil {
 		tid = th.ThreadID()
 	}
-	r := &Goroutine{
+	if g.Unreadable != nil {
+		return &Goroutine{Unreadable: g.Unreadable.Error()}
+	}
+	return &Goroutine{
 		ID:             g.ID,
 		CurrentLoc:     ConvertLocation(g.CurrentLoc),
 		UserCurrentLoc: ConvertLocation(g.UserCurrent()),
@@ -266,10 +269,6 @@ func ConvertGoroutine(g *proc.G) *Goroutine {
 		ThreadID:       tid,
 		Labels:         g.Labels(),
 	}
-	if g.Unreadable != nil {
-		r.Unreadable = g.Unreadable.Error()
-	}
-	return r
 }
 
 // ConvertLocation converts from proc.Location to api.Location.