From aac7a47469b32680472168669e046af34287e462 Mon Sep 17 00:00:00 2001
From: Justin Chadwell <me@jedevc.com>
Date: Tue, 28 Nov 2023 10:11:51 +0000
Subject: [PATCH] build: fix incorrect solve opt platform from being set

This regression was introduced in 616fb3e55cbc85647026f6e409af17e1011a85c4,
with the node resolution refactor.

The core issue here is just that we would unconditionally set the
solve opt's platform to the default current platform, which was
incorrect. We can prevent this easily by having a special case for the
default case, like we had before, and then not setting the platforms
field on this (which keeping the resolution behavior which was
introduced).

Signed-off-by: Justin Chadwell <me@jedevc.com>
---
 build/driver.go      | 26 +++++++++++++++++---------
 build/driver_test.go |  2 ++
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/build/driver.go b/build/driver.go
index c2e01cbb..0096459e 100644
--- a/build/driver.go
+++ b/build/driver.go
@@ -164,28 +164,36 @@ func (r *nodeResolver) resolve(ctx context.Context, ps []specs.Platform, pw prog
 		return nil, true, nil
 	}
 
-	if len(ps) == 0 {
-		ps = []specs.Platform{platforms.DefaultSpec()}
-	}
-
 	perfect := true
 	nodeIdxs := make([]int, 0)
-	for _, p := range ps {
-		idx := r.get(p, matcher, additional)
+	if len(ps) == 0 {
+		idx := r.get(platforms.DefaultSpec(), matcher, additional)
 		if idx == -1 {
 			idx = 0
 			perfect = false
 		}
 		nodeIdxs = append(nodeIdxs, idx)
+	} else {
+		for _, p := range ps {
+			idx := r.get(p, matcher, additional)
+			if idx == -1 {
+				idx = 0
+				perfect = false
+			}
+			nodeIdxs = append(nodeIdxs, idx)
+		}
 	}
 
 	var nodes []*resolvedNode
 	for i, idx := range nodeIdxs {
-		nodes = append(nodes, &resolvedNode{
+		node := &resolvedNode{
 			resolver:    r,
 			driverIndex: idx,
-			platforms:   []specs.Platform{ps[i]},
-		})
+		}
+		if len(ps) > 0 {
+			node.platforms = []specs.Platform{ps[i]}
+		}
+		nodes = append(nodes, node)
 	}
 	nodes = recombineNodes(nodes)
 	if _, err := r.boot(ctx, nodeIdxs, pw); err != nil {
diff --git a/build/driver_test.go b/build/driver_test.go
index 068ec7ee..63c79728 100644
--- a/build/driver_test.go
+++ b/build/driver_test.go
@@ -22,6 +22,7 @@ func TestFindDriverSanity(t *testing.T) {
 	require.Len(t, res, 1)
 	require.Equal(t, 0, res[0].driverIndex)
 	require.Equal(t, "aaa", res[0].Node().Builder)
+	require.Equal(t, []specs.Platform{platforms.DefaultSpec()}, res[0].platforms)
 }
 
 func TestFindDriverEmpty(t *testing.T) {
@@ -227,6 +228,7 @@ func TestSelectNodeCurrentPlatform(t *testing.T) {
 	require.True(t, perfect)
 	require.Len(t, res, 1)
 	require.Equal(t, "bbb", res[0].Node().Builder)
+	require.Empty(t, res[0].platforms)
 }
 
 func TestSelectNodeAdditionalPlatforms(t *testing.T) {