From d7dda4e4360861354dbd61fc8e19117ef4a412db Mon Sep 17 00:00:00 2001
From: Kristin Laemmert <mildwonkey@users.noreply.github.com>
Date: Tue, 30 Apr 2019 14:34:01 -0400
Subject: [PATCH] states/statefile: upgrade legacy dependency syntax (#21159)

We used to allow "foo.1" etc as a reference, but now it's "foo[1]".
---
 .../testdata/roundtrip/v3-simple.in.tfstate    |  5 +++--
 .../testdata/roundtrip/v3-simple.out.tfstate   |  5 +++--
 states/statefile/version3_upgrade.go           | 18 +++++++++++++++++-
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/states/statefile/testdata/roundtrip/v3-simple.in.tfstate b/states/statefile/testdata/roundtrip/v3-simple.in.tfstate
index b9d9889ef..ec8ceeb3a 100644
--- a/states/statefile/testdata/roundtrip/v3-simple.in.tfstate
+++ b/states/statefile/testdata/roundtrip/v3-simple.in.tfstate
@@ -20,7 +20,8 @@
                     "type": "null_resource",
                     "depends_on": [
                         "null_resource.foo.*",
-                        "null_resource.foobar"
+                        "null_resource.foobar",
+                        "null_resource.foobar.1"
                     ],
                     "primary": {
                         "id": "5388490630832483079",
@@ -87,4 +88,4 @@
             "depends_on": []
         }
     ]
-}
+}
\ No newline at end of file
diff --git a/states/statefile/testdata/roundtrip/v3-simple.out.tfstate b/states/statefile/testdata/roundtrip/v3-simple.out.tfstate
index 38f325d66..ba77ddc7f 100644
--- a/states/statefile/testdata/roundtrip/v3-simple.out.tfstate
+++ b/states/statefile/testdata/roundtrip/v3-simple.out.tfstate
@@ -25,7 +25,8 @@
                     },
                     "depends_on": [
                         "null_resource.foo",
-                        "null_resource.foobar"
+                        "null_resource.foobar",
+                        "null_resource.foobar[1]"
                     ]
                 }
             ]
@@ -74,4 +75,4 @@
             ]
         }
     ]
-}
+}
\ No newline at end of file
diff --git a/states/statefile/version3_upgrade.go b/states/statefile/version3_upgrade.go
index 7ec1c9465..2cbe8a53c 100644
--- a/states/statefile/version3_upgrade.go
+++ b/states/statefile/version3_upgrade.go
@@ -301,7 +301,7 @@ func upgradeInstanceObjectV3ToV4(rsOld *resourceStateV2, isOld *instanceStateV2,
 
 	dependencies := make([]string, len(rsOld.Dependencies))
 	for i, v := range rsOld.Dependencies {
-		dependencies[i] = strings.TrimSuffix(v, ".*")
+		dependencies[i] = parseLegacyDependency(v)
 	}
 
 	return &instanceObjectStateV4{
@@ -413,3 +413,19 @@ func simplifyImpliedValueType(ty cty.Type) cty.Type {
 		return ty
 	}
 }
+
+func parseLegacyDependency(s string) string {
+	parts := strings.Split(s, ".")
+	ret := parts[0]
+	for _, part := range parts[1:] {
+		if part == "*" {
+			break
+		}
+		if i, err := strconv.Atoi(part); err == nil {
+			ret = ret + fmt.Sprintf("[%d]", i)
+			break
+		}
+		ret = ret + "." + part
+	}
+	return ret
+}