From 9a2dc3fe150a03ccb4f086b05d8a8249c9e6c37f Mon Sep 17 00:00:00 2001
From: Jesse Duffield <jessedduffield@gmail.com>
Date: Wed, 19 Aug 2020 08:26:22 +1000
Subject: [PATCH] stop crash due to context stack not being initialized

---
 pkg/gui/commits_panel.go      |  2 +-
 pkg/gui/context.go            | 19 ++++++++++++++-----
 pkg/gui/gui.go                | 10 ++++++----
 pkg/gui/layout.go             |  2 +-
 pkg/gui/line_by_line_panel.go |  2 +-
 5 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/pkg/gui/commits_panel.go b/pkg/gui/commits_panel.go
index 7f2df104b..6e5e2d201 100644
--- a/pkg/gui/commits_panel.go
+++ b/pkg/gui/commits_panel.go
@@ -96,7 +96,7 @@ func (gui *Gui) refreshCommits() error {
 
 	go func() {
 		_ = gui.refreshCommitsWithLimit()
-		if gui.g.CurrentView() == gui.getCommitFilesView() || (gui.currentContext().GetKey() == gui.Contexts.PatchBuilding.Context.GetKey()) {
+		if gui.g.CurrentView() == gui.getCommitFilesView() || (gui.currentContextKey() == gui.Contexts.PatchBuilding.Context.GetKey()) {
 			_ = gui.refreshCommitFilesView()
 		}
 		wg.Done()
diff --git a/pkg/gui/context.go b/pkg/gui/context.go
index 522932664..3c5dedde5 100644
--- a/pkg/gui/context.go
+++ b/pkg/gui/context.go
@@ -208,12 +208,17 @@ func (gui *Gui) renderContextStack() string {
 	return result
 }
 
-func (gui *Gui) currentContext() Context {
-	return gui.State.ContextStack[len(gui.State.ContextStack)-1]
+func (gui *Gui) currentContextKey() string {
+	// on startup the stack can be empty so we'll return an empty string in that case
+	if len(gui.State.ContextStack) == 0 {
+		return ""
+	}
+
+	return gui.State.ContextStack[len(gui.State.ContextStack)-1].GetKey()
 }
 
-func (gui *Gui) createContextTree() {
-	gui.Contexts = ContextTree{
+func (gui *Gui) contextTree() ContextTree {
+	return ContextTree{
 		Status: SimpleContextNode{
 			Context: BasicContext{
 				OnFocus:  gui.handleStatusSelect,
@@ -329,8 +334,10 @@ func (gui *Gui) createContextTree() {
 			},
 		},
 	}
+}
 
-	gui.State.ViewContextMap = map[string]Context{
+func (gui *Gui) initialViewContextMap() map[string]Context {
+	return map[string]Context{
 		"status":        gui.Contexts.Status.Context,
 		"files":         gui.Contexts.Files.Context,
 		"branches":      gui.Contexts.Branches.Context,
@@ -344,7 +351,9 @@ func (gui *Gui) createContextTree() {
 		"main":          gui.Contexts.Normal.Context,
 		"secondary":     gui.Contexts.Normal.Context,
 	}
+}
 
+func (gui *Gui) setInitialViewContexts() {
 	// arguably we should only have our ViewContextMap and we should do away with
 	// contexts on views, or vice versa
 	for viewName, context := range gui.State.ViewContextMap {
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 1c0178fe8..cc083b4de 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -282,10 +282,11 @@ func (gui *Gui) resetState() {
 				EditHistory:   stack.New(),
 			},
 		},
-		SideView:   nil,
-		Ptmx:       nil,
-		FilterPath: prevFilterPath,
-		Diff:       prevDiff,
+		SideView:       nil,
+		Ptmx:           nil,
+		FilterPath:     prevFilterPath,
+		Diff:           prevDiff,
+		ViewContextMap: gui.initialViewContextMap(),
 	}
 }
 
@@ -306,6 +307,7 @@ func NewGui(log *logrus.Entry, gitCommand *commands.GitCommand, oSCommand *comma
 
 	gui.resetState()
 	gui.State.FilterPath = filterPath
+	gui.Contexts = gui.contextTree()
 
 	gui.watchFilesForChanges()
 
diff --git a/pkg/gui/layout.go b/pkg/gui/layout.go
index 094c7271c..bc59bb5e2 100644
--- a/pkg/gui/layout.go
+++ b/pkg/gui/layout.go
@@ -337,7 +337,7 @@ func (gui *Gui) layout(g *gocui.Gui) error {
 }
 
 func (gui *Gui) onInitialViewsCreation() error {
-	gui.createContextTree()
+	gui.setInitialViewContexts()
 
 	if err := gui.switchContext(gui.Contexts.Files.Context); err != nil {
 		return err
diff --git a/pkg/gui/line_by_line_panel.go b/pkg/gui/line_by_line_panel.go
index 6bec51308..4ae8e741a 100644
--- a/pkg/gui/line_by_line_panel.go
+++ b/pkg/gui/line_by_line_panel.go
@@ -234,7 +234,7 @@ func (gui *Gui) refreshMainView() error {
 	var includedLineIndices []int
 	// I'd prefer not to have knowledge of contexts using this file but I'm not sure
 	// how to get around this
-	if gui.currentContext().GetKey() == gui.Contexts.PatchBuilding.Context.GetKey() {
+	if gui.currentContextKey() == gui.Contexts.PatchBuilding.Context.GetKey() {
 		filename := gui.getSelectedCommitFileName()
 		includedLineIndices = gui.GitCommand.PatchManager.GetFileIncLineIndices(filename)
 	}