don't let patch manager ever be nil

pkg/commands/git.go

@@ -109,7 +109,7 @@ func NewGitCommand(log *logrus.Entry, osCommand *OSCommand, tr *i18n.Localizer,
 		return nil, err
 	}
 
-	return &GitCommand{
+	gitCommand := &GitCommand{
 		Log:                log,
 		OSCommand:          osCommand,
 		Tr:                 tr,
@@ -120,7 +120,11 @@ func NewGitCommand(log *logrus.Entry, osCommand *OSCommand, tr *i18n.Localizer,
 		getLocalGitConfig:  gitconfig.Local,
 		removeFile:         os.RemoveAll,
 		DotGitDir:          dotGitDir,
-	}, nil
+	}
+
+	gitCommand.PatchManager = NewPatchManager(log, gitCommand.ApplyPatch)
+
+	return gitCommand, nil
 }
 
 func findDotGitDir(stat func(string) (os.FileInfo, error), readFile func(filename string) ([]byte, error)) (string, error) {

pkg/commands/patch_manager.go

@@ -25,21 +25,23 @@ type PatchManager struct {
 }
 
 // NewPatchManager returns a new PatchModifier
-func NewPatchManager(log *logrus.Entry, applyPatch applyPatchFunc, commitSha string, diffMap map[string]string) *PatchManager {
-	infoMap := map[string]*fileInfo{}
+func NewPatchManager(log *logrus.Entry, applyPatch applyPatchFunc) *PatchManager {
+	return &PatchManager{
+		Log:        log,
+		ApplyPatch: applyPatch,
+	}
+}
+
+// NewPatchManager returns a new PatchModifier
+func (p *PatchManager) Start(commitSha string, diffMap map[string]string) {
+	p.CommitSha = commitSha
+	p.fileInfoMap = map[string]*fileInfo{}
 	for filename, diff := range diffMap {
-		infoMap[filename] = &fileInfo{
+		p.fileInfoMap[filename] = &fileInfo{
 			mode: UNSELECTED,
 			diff: diff,
 		}
 	}
-
-	return &PatchManager{
-		Log:         log,
-		fileInfoMap: infoMap,
-		CommitSha:   commitSha,
-		ApplyPatch:  applyPatch,
-	}
 }
 
 func (p *PatchManager) AddFile(filename string) {
@@ -200,3 +202,13 @@ func (p *PatchManager) ApplyPatches(reverse bool) error {
 
 	return nil
 }
+
+// clears the patch
+func (p *PatchManager) Reset() {
+	p.CommitSha = ""
+	p.fileInfoMap = map[string]*fileInfo{}
+}
+
+func (p *PatchManager) IsEmpty() bool {
+	return p != nil && p.CommitSha == "" || len(p.fileInfoMap) == 0
+}

pkg/commands/patch_rebases.go

@@ -22,7 +22,7 @@ func (c *GitCommand) DeletePatchesFromCommit(commits []*Commit, commitIndex int,
 	}
 
 	c.onSuccessfulContinue = func() error {
-		c.PatchManager = nil
+		c.PatchManager.Reset()
 		return nil
 	}
 
@@ -50,7 +50,7 @@ func (c *GitCommand) MovePatchToSelectedCommit(commits []*Commit, sourceCommitId
 		}
 
 		c.onSuccessfulContinue = func() error {
-			c.PatchManager = nil
+			c.PatchManager.Reset()
 			return nil
 		}
 
@@ -121,7 +121,7 @@ func (c *GitCommand) MovePatchToSelectedCommit(commits []*Commit, sourceCommitId
 		}
 
 		c.onSuccessfulContinue = func() error {
-			c.PatchManager = nil
+			c.PatchManager.Reset()
 			return nil
 		}
 
@@ -161,7 +161,7 @@ func (c *GitCommand) PullPatchIntoIndex(commits []*Commit, commitIdx int, p *Pat
 			return err
 		}
 
-		c.PatchManager = nil
+		c.PatchManager.Reset()
 		return nil
 	}