Fixes accidental deletion of Repository resource from state (#1750)

Currently when the user does not authenticate the provider, refreshing a GithubRepository resource drops it from the
state, which is unexpected and very confusing.

The root cause of this is: when AnonymousHTTPClient is used, owner == "" and this causes resourceGithubRepositoryRead to
issue requests to non-existent URLs such as https://github.com//myrepo and subsequently interpret 404 as a reason to
drop the resource from the state.

The suggested fix consults the resource data to infer the appropriate owner to use instead of the empty owner.

Co-authored-by: Keegan Campbell <me@kfcampbell.com>

github/resource_github_repository.go

@@ -593,9 +593,16 @@ func resourceGithubRepositoryCreate(d *schema.ResourceData, meta interface{}) er
 
 func resourceGithubRepositoryRead(d *schema.ResourceData, meta interface{}) error {
 	client := meta.(*Owner).v3client
+
 	owner := meta.(*Owner).name
 	repoName := d.Id()
 
+	// When the user has not authenticated the provider, AnonymousHTTPClient is used, therefore owner == "". In this
+	// case lookup the owner in the data, and use that, if present.
+	if explicitOwner, _, ok := resourceGithubParseFullName(d); ok && owner == "" {
+		owner = explicitOwner
+	}
+
 	ctx := context.WithValue(context.Background(), ctxId, d.Id())
 	if !d.IsNewResource() {
 		ctx = context.WithValue(ctx, ctxEtag, d.Get("etag").(string))
@@ -942,3 +949,23 @@ func flattenSecurityAndAnalysis(securityAndAnalysis *github.SecurityAndAnalysis)
 
 	return []interface{}{securityAndAnalysisMap}
 }
+
+// In case full_name can be determined from the data, parses it into an org and repo name proper. For example,
+// resourceGithubParseFullName will return "myorg", "myrepo", true when full_name is "myorg/myrepo".
+func resourceGithubParseFullName(resourceDataLike interface {
+	GetOk(string) (interface{}, bool)
+}) (string, string, bool) {
+	x, ok := resourceDataLike.GetOk("full_name")
+	if !ok {
+		return "", "", false
+	}
+	s, ok := x.(string)
+	if !ok || s == "" {
+		return "", "", false
+	}
+	parts := strings.Split(s, "/")
+	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
+		return "", "", false
+	}
+	return parts[0], parts[1], true
+}

github/resource_github_repository_test.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/hashicorp/terraform-plugin-sdk/helper/acctest"
 	"github.com/hashicorp/terraform-plugin-sdk/helper/resource"
+	"github.com/stretchr/testify/assert"
 )
 
 func TestAccGithubRepositories(t *testing.T) {
@@ -1407,3 +1408,21 @@ func reconfigureVisibility(config, visibility string) string {
 	)
 	return newConfig
 }
+
+type resourceDataLike map[string]interface{}
+
+func (d resourceDataLike) GetOk(key string) (interface{}, bool) {
+	v, ok := d[key]
+	return v, ok
+}
+
+func TestResourceGithubParseFullName(t *testing.T) {
+	repo, org, ok := resourceGithubParseFullName(resourceDataLike(map[string]interface{}{"full_name": "myrepo/myorg"}))
+	assert.True(t, ok)
+	assert.Equal(t, "myrepo", repo)
+	assert.Equal(t, "myorg", org)
+	_, _, ok = resourceGithubParseFullName(resourceDataLike(map[string]interface{}{}))
+	assert.False(t, ok)
+	_, _, ok = resourceGithubParseFullName(resourceDataLike(map[string]interface{}{"full_name": "malformed"}))
+	assert.False(t, ok)
+}