Allow merging with overwrite

This means that additional indexex are allowed to overwrite official boards.

Author: cmaglie

Diff for: go.mod

@@ -14,6 +14,7 @@ require (
 	go.bug.st/downloader/v2 v2.1.1
 	go.bug.st/relaxed-semver v0.10.2
 	go.bug.st/serial v1.3.2
+	golang.org/x/exp v0.0.0-20230321023759-10a507213a29
 	gopkg.in/yaml.v3 v3.0.1
 )
 

Diff for: go.sum

@@ -341,6 +341,8 @@ golang.org/x/exp v0.0.0-20191227195350-da58074b4299/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
+golang.org/x/exp v0.0.0-20230321023759-10a507213a29 h1:ooxPy7fPvB4kwsA2h+iBNHkAbp/4JxTSwCmvdjEYmug=
+golang.org/x/exp v0.0.0-20230321023759-10a507213a29/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=

Diff for: indexes/firmwareindex/firmwareindex.go

@@ -28,6 +28,7 @@ import (
 	"github.com/arduino/go-paths-helper"
 	"github.com/sirupsen/logrus"
 	semver "go.bug.st/relaxed-semver"
+	"golang.org/x/exp/slices"
 )
 
 // Index represents Boards struct as seen from module_firmware_index.json file.
@@ -128,7 +129,14 @@ func LoadIndexNoSign(jsonIndexFile *paths.Path) (*Index, error) {
 // MergeWith merge this index with the other given index (the boards from the other index)
 // are added to this one.
 func (i *Index) MergeWith(j *Index) {
-	i.Boards = append(i.Boards, j.Boards...)
+	for _, boardToAdd := range j.Boards {
+		idx := slices.IndexFunc(i.Boards, func(x *IndexBoard) bool { return x.Overlaps(boardToAdd) })
+		if idx == -1 {
+			i.Boards = append(i.Boards, boardToAdd)
+		} else {
+			i.Boards[idx] = boardToAdd
+		}
+	}
 	i.IsTrusted = i.IsTrusted && j.IsTrusted
 }
 
@@ -142,6 +150,13 @@ func (i *Index) GetBoard(fqbn string) *IndexBoard {
 	return nil
 }
 
+// Overlaps returns true if the two IndexBoard represent the same board.
+func (b *IndexBoard) Overlaps(x *IndexBoard) bool {
+	return b.Fqbn == x.Fqbn &&
+		b.Module == x.Module &&
+		b.Name == x.Name
+}
+
 // GetFirmware returns the specified IndexFirmware version for this board.
 // Returns nil if version is not found.
 func (b *IndexBoard) GetFirmware(version string) *IndexFirmware {