fix segfault on line by line panel

The state object is sometimes undefined in the onclick method of the
line by line panel. Because we set it to nil in a bunch of places,
I've decided to just change the main context to 'normal' before setting
it to nil anywhere. That way the keybindings for the line by line panel
won't get executed and we won't get a segfault.

8 files changed, 19 insertions, 23 deletions

diff --git a/pkg/gui/commit_files_panel.go b/pkg/gui/commit_files_panel.go
index 42afc6c94..b4a08625a 100644
--- a/pkg/gui/commit_files_panel.go
+++ b/pkg/gui/commit_files_panel.go
@@ -29,7 +29,9 @@ func (gui *Gui) handleCommitFileSelect(g *gocui.Gui, v *gocui.View) error {
 	}
 
 	gui.getMainView().Title = "Patch"
-	gui.State.Panels.LineByLine = nil
+	if gui.currentViewName() == "commitFiles" {
+		gui.handleEscapeLineByLinePanel()
+	}
 
 	commitFile := gui.getSelectedCommitFile(g)
 	if commitFile == nil {
@@ -194,9 +196,7 @@ func (gui *Gui) enterCommitFile(selectedLineIdx int) error {
 			}
 		}
 
-		if err := gui.changeMainViewsContext("patch-building"); err != nil {
-			return err
-		}
+		gui.changeMainViewsContext("patch-building")
 		if err := gui.switchFocus(gui.g, gui.getCommitFilesView(), gui.getMainView()); err != nil {
 			return err
 		}
diff --git a/pkg/gui/commits_panel.go b/pkg/gui/commits_panel.go
index abc6b47ec..d25d9b239 100644
--- a/pkg/gui/commits_panel.go
+++ b/pkg/gui/commits_panel.go
@@ -49,7 +49,7 @@ func (gui *Gui) handleCommitSelect(g *gocui.Gui, v *gocui.View) error {
 
 	gui.getMainView().Title = "Patch"
 	gui.getSecondaryView().Title = "Custom Patch"
-	gui.State.Panels.LineByLine = nil
+	gui.handleEscapeLineByLinePanel()
 
 	commit := gui.getSelectedCommit(g)
 	if commit == nil {
diff --git a/pkg/gui/context.go b/pkg/gui/context.go
index 6424a8707..53b884cc7 100644
--- a/pkg/gui/context.go
+++ b/pkg/gui/context.go
@@ -4,9 +4,9 @@ package gui
 // which currently just means a context that affects both the main and secondary views
 // other views can have their context changed directly but this function helps
 // keep the main and secondary views in sync
-func (gui *Gui) changeMainViewsContext(context string) error {
+func (gui *Gui) changeMainViewsContext(context string) {
 	if gui.State.MainContext == context {
-		return nil
+		return
 	}
 
 	switch context {
@@ -16,5 +16,5 @@ func (gui *Gui) changeMainViewsContext(context string) error {
 	}
 
 	gui.State.MainContext = context
-	return nil
+	return
 }
diff --git a/pkg/gui/files_panel.go b/pkg/gui/files_panel.go
index 2128d67a7..1a35210da 100644
--- a/pkg/gui/files_panel.go
+++ b/pkg/gui/files_panel.go
@@ -173,9 +173,7 @@ func (gui *Gui) enterFile(forceSecondaryFocused bool, selectedLineIdx int) error
 	if file.HasMergeConflicts {
 		return gui.createErrorPanel(gui.g, gui.Tr.SLocalize("FileStagingRequirements"))
 	}
-	if err := gui.changeMainViewsContext("staging"); err != nil {
-		return err
-	}
+	gui.changeMainViewsContext("staging")
 	if err := gui.switchFocus(gui.g, gui.getFilesView(), gui.getMainView()); err != nil {
 		return err
 	}
@@ -497,9 +495,7 @@ func (gui *Gui) handleSwitchToMerge(g *gocui.Gui, v *gocui.View) error {
 	if !file.HasInlineMergeConflicts {
 		return gui.createErrorPanel(g, gui.Tr.SLocalize("FileNoMergeCons"))
 	}
-	if err := gui.changeMainViewsContext("merging"); err != nil {
-		return err
-	}
+	gui.changeMainViewsContext("merging")
 	if err := gui.switchFocus(g, v, gui.getMainView()); err != nil {
 		return err
 	}
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 7da7f53fa..c8e8453c5 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -348,9 +348,7 @@ func (gui *Gui) onFocusLost(v *gocui.View, newView *gocui.View) error {
 		}
 	case "main":
 		// if we have lost focus to a first-class panel, we need to do some cleanup
-		if err := gui.changeMainViewsContext("normal"); err != nil {
-			return err
-		}
+		gui.changeMainViewsContext("normal")
 	case "commitFiles":
 		if gui.State.MainContext != "patch-building" {
 			if _, err := gui.g.SetViewOnBottom(v.Name()); err != nil {
@@ -698,9 +696,7 @@ func (gui *Gui) layout(g *gocui.Gui) error {
 }
 
 func (gui *Gui) onInitialViewsCreation() error {
-	if err := gui.changeMainViewsContext("normal"); err != nil {
-		return err
-	}
+	gui.changeMainViewsContext("normal")
 
 	gui.getBranchesView().Context = "local-branches"
 	gui.getCommitsView().Context = "branch-commits"
diff --git a/pkg/gui/line_by_line_panel.go b/pkg/gui/line_by_line_panel.go
index 8c46fd134..c9e06eeba 100644
--- a/pkg/gui/line_by_line_panel.go
+++ b/pkg/gui/line_by_line_panel.go
@@ -314,3 +314,8 @@ func (gui *Gui) handleToggleSelectHunk(g *gocui.Gui, v *gocui.View) error {
 
 	return gui.focusSelection(state.SelectMode == HUNK)
 }
+
+func (gui *Gui) handleEscapeLineByLinePanel() {
+	gui.changeMainViewsContext("normal")
+	gui.State.Panels.LineByLine = nil
+}
diff --git a/pkg/gui/patch_building_panel.go b/pkg/gui/patch_building_panel.go
index 8a3d5db89..22e7c4b4a 100644
--- a/pkg/gui/patch_building_panel.go
+++ b/pkg/gui/patch_building_panel.go
@@ -87,8 +87,7 @@ func (gui *Gui) handleRemoveSelectionFromPatch(g *gocui.Gui, v *gocui.View) erro
 }
 
 func (gui *Gui) handleEscapePatchBuildingPanel(g *gocui.Gui, v *gocui.View) error {
-	gui.State.Panels.LineByLine = nil
-	gui.changeMainViewsContext("normal")
+	gui.handleEscapeLineByLinePanel()
 
 	if gui.GitCommand.PatchManager.IsEmpty() {
 		gui.GitCommand.PatchManager.Reset()
diff --git a/pkg/gui/staging_panel.go b/pkg/gui/staging_panel.go
index a6eecb8b0..5fa7317de 100644
--- a/pkg/gui/staging_panel.go
+++ b/pkg/gui/staging_panel.go
@@ -94,7 +94,7 @@ func (gui *Gui) handleTogglePanel(g *gocui.Gui, v *gocui.View) error {
 }
 
 func (gui *Gui) handleStagingEscape(g *gocui.Gui, v *gocui.View) error {
-	gui.State.Panels.LineByLine = nil
+	gui.handleEscapeLineByLinePanel()
 
 	return gui.switchFocus(gui.g, nil, gui.getFilesView())
 }