Add config for auto-forwarding branches after fetching

pkg/config/user_config.go

@@ -244,6 +244,9 @@ type GitConfig struct {
 	AutoFetch bool `yaml:"autoFetch"`
 	// If true, periodically refresh files and submodules
 	AutoRefresh bool `yaml:"autoRefresh"`
+	// If not "none", lazygit will automatically forward branches to their upstream after fetching. Applies to branches that are not the currently checked out branch, and only to those that are strictly behind their upstream (as opposed to diverged).
+	// Possible values: 'none' | 'onlyMainBranches' | 'allBranches'
+	AutoForwardBranches string `yaml:"autoForwardBranches" jsonschema:"enum=none,enum=onlyMainBranches,enum=allBranches"`
 	// If true, pass the --all arg to git fetch
 	FetchAll bool `yaml:"fetchAll"`
 	// If true, lazygit will automatically stage files that used to have merge
@@ -822,6 +825,7 @@ func GetDefaultConfig() *UserConfig {
 			MainBranches:                 []string{"master", "main"},
 			AutoFetch:                    true,
 			AutoRefresh:                  true,
+			AutoForwardBranches:          "onlyMainBranches",
 			FetchAll:                     true,
 			AutoStageResolvedConflicts:   true,
 			BranchLogCmd:                 "git log --graph --color=always --abbrev-commit --decorate --date=relative --pretty=medium {{branchName}} --",