From eb1acac350ab831647820ae3ee4b304c7a121df9 Mon Sep 17 00:00:00 2001
From: Piotr Komborski <piotr.komborski@gmail.com>
Date: Wed, 30 Sep 2020 14:33:27 +0100
Subject: [PATCH] Overwrite node if key exists

but value doesn't match or append if key does not exist

This fixes a bug with exploding anchors not overwriting nodes reported
in https://github.com/mikefarah/yq/issues/546

Test case:
```
a: &first_anchor
  foo: bar
  first: first
b: &second_anchor
  foo: bazz
  second: second
c:
  <<: *first_anchor
  <<: *second_anchor
```

Output:

```
a:
  foo: bar
  first: first
b:
  foo: bazz
  second: second
c:
  foo: bazz
  first: first
  second: second
```

foo is properly overwritten by *second_anchor
---
 cmd/utils.go | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/cmd/utils.go b/cmd/utils.go
index 9b1ca726..754c9332 100644
--- a/cmd/utils.go
+++ b/cmd/utils.go
@@ -149,10 +149,15 @@ func writeString(writer io.Writer, txt string) error {
 	return errorWriting
 }
 
-func setIfNotThere(node *yaml.Node, key string, value *yaml.Node) {
+func overwriteOrSet(node *yaml.Node, key string, value *yaml.Node) {
 	for index := 0; index < len(node.Content); index = index + 2 {
 		keyNode := node.Content[index]
-		if keyNode.Value == key {
+		valueNode := node.Content[index+1]
+		if keyNode.Value == key && valueNode.Value == value.Value {
+			return
+		}
+		if keyNode.Value == key && valueNode.Value != value.Value {
+			node.Content[index+1] = value
 			return
 		}
 	}
@@ -170,7 +175,7 @@ func applyAlias(node *yaml.Node, alias *yaml.Node) {
 		keyNode := alias.Content[index]
 		log.Debugf("applying alias key %v", keyNode.Value)
 		valueNode := alias.Content[index+1]
-		setIfNotThere(node, keyNode.Value, valueNode)
+		overwriteOrSet(node, keyNode.Value, valueNode)
 	}
 }