Add command to find base commit for creating a fixup

pkg/commands/git.go

@@ -21,6 +21,7 @@ import (
 
 // GitCommand is our main git interface
 type GitCommand struct {
+	Blame       *git_commands.BlameCommands
 	Branch      *git_commands.BranchCommands
 	Commit      *git_commands.CommitCommands
 	Config      *git_commands.ConfigCommands
@@ -160,6 +161,7 @@ func NewGitCommandAux(
 	patchCommands := git_commands.NewPatchCommands(gitCommon, rebaseCommands, commitCommands, statusCommands, stashCommands, patchBuilder)
 	bisectCommands := git_commands.NewBisectCommands(gitCommon)
 	worktreeCommands := git_commands.NewWorktreeCommands(gitCommon)
+	blameCommands := git_commands.NewBlameCommands(gitCommon)
 
 	branchLoader := git_commands.NewBranchLoader(cmn, cmd, branchCommands.CurrentBranchInfo, configCommands)
 	commitFileLoader := git_commands.NewCommitFileLoader(cmn, cmd)
@@ -171,6 +173,7 @@ func NewGitCommandAux(
 	tagLoader := git_commands.NewTagLoader(cmn, cmd)
 
 	return &GitCommand{
+		Blame:       blameCommands,
 		Branch:      branchCommands,
 		Commit:      commitCommands,
 		Config:      configCommands,

pkg/commands/git_commands/blame.go

@@ -0,0 +1,33 @@
+package git_commands
+
+import (
+	"fmt"
+)
+
+type BlameCommands struct {
+	*GitCommon
+}
+
+func NewBlameCommands(gitCommon *GitCommon) *BlameCommands {
+	return &BlameCommands{
+		GitCommon: gitCommon,
+	}
+}
+
+// Blame a range of lines. For each line, output the hash of the commit where
+// the line last changed, then a space, then a description of the commit (author
+// and date), another space, and then the line. For example:
+//
+//	ac90ebac688fe8bc2ffd922157a9d2c54681d2aa (Stefan Haller 2023-08-01 14:54:56 +0200 11) func NewBlameCommands(gitCommon *GitCommon) *BlameCommands {
+//	ac90ebac688fe8bc2ffd922157a9d2c54681d2aa (Stefan Haller 2023-08-01 14:54:56 +0200 12) 	return &BlameCommands{
+//	ac90ebac688fe8bc2ffd922157a9d2c54681d2aa (Stefan Haller 2023-08-01 14:54:56 +0200 13) 		GitCommon: gitCommon,
+func (self *BlameCommands) BlameLineRange(filename string, commit string, firstLine int, numLines int) (string, error) {
+	cmdArgs := NewGitCmd("blame").
+		Arg("-l").
+		Arg(fmt.Sprintf("-L%d,+%d", firstLine, numLines)).
+		Arg(commit).
+		Arg("--").
+		Arg(filename)
+
+	return self.cmd.New(cmdArgs.ToArgv()).RunWithOutput()
+}

pkg/commands/git_commands/commit.go

@@ -198,6 +198,20 @@ func (self *CommitCommands) GetCommitMessagesFirstLine(shas []string) (string, e
 	return self.cmd.New(cmdArgs).DontLog().RunWithOutput()
 }
 
+// Example output:
+//
+//	cd50c79ae Preserve the commit message correctly even if the description has blank lines
+//	3ebba5f32 Add test demonstrating a bug with preserving the commit message
+//	9a423c388 Remove unused function
+func (self *CommitCommands) GetShasAndCommitMessagesFirstLine(shas []string) (string, error) {
+	cmdArgs := NewGitCmd("show").
+		Arg("--no-patch", "--pretty=format:%h %s").
+		Arg(shas...).
+		ToArgv()
+
+	return self.cmd.New(cmdArgs).DontLog().RunWithOutput()
+}
+
 func (self *CommitCommands) GetCommitsOneline(shas []string) (string, error) {
 	cmdArgs := NewGitCmd("show").
 		Arg("--no-patch", "--oneline").

pkg/commands/git_commands/diff.go

@@ -78,3 +78,11 @@ func (self *DiffCommands) OpenDiffToolCmdObj(opts DiffToolCmdOptions) oscommands
 		Arg("--", opts.Filepath).
 		ToArgv())
 }
+
+func (self *DiffCommands) DiffIndexCmdObj(diffArgs ...string) oscommands.ICmdObj {
+	return self.cmd.New(
+		NewGitCmd("diff-index").
+			Arg("--submodule", "--no-ext-diff", "--no-color", "--patch").
+			Arg(diffArgs...).ToArgv(),
+	)
+}