Stage, Unstage, and the Index Editor
Git’s Index tracks which changes in the Working Tree have been selected for inclusion in the next commit.
Changes must be added to the Index before they can be added in a new commit.
Common Staging Operations in SmartGit
SmartGit provides the following options for modifying the selection of changes:
- Stage adds a new, modified, or deleted file to the index. For files selected in the Files View, all changed files in the selection will be staged. If no files are selected, SmartGit will display the Stage View dialog, showing files eligible for staging and allowing you to choose which files to include or exclude from the next commit. Once one or more files have been staged, the Files View will split, with the bottom half will showing already staged files.
- Unstage removes files from the index (i.e., excludes them from the next commit). Any selected staged files will be unstaged. If no staged files are chosen, SmartGit will display the Stage View, where you can deselect files unstage them.
- The Changes View is invaluable during all staging operations, allowing you to compare changes made to a selected file easily. It also allows you to stage and unstage individual Hunks, should you wish to avoid staging all changes in a file.
- Advanced - The Index Editor allows direct editing of the Index’s contents for a selected file. This lets you add or remove specific content to and from the Index.
Behavior of Stage
The outcome of the Stage command depends on whether the file is tracked or untracked:
- Untracked (new) file: If you use Stage (e.g., via Local | Stage), the file will be marked for addition to the repository.
- Tracked file: Using Stage on a tracked file includes any modifications in the next commit, such as added, modified, or deleted lines.
- Previously tracked but deleted file: The file will be deleted in the next commit.
Conversely, the Unstage command (via Local | Unstage) removes the selected file from in the Index, ensuring its changes are not included in the next commit.
Tip
The behavior of the Changes View varies depending on the file’s staging status:
- Unstaged file: The Changes View shows differences between the Working Tree and the Index.
- Staged file: The Changes View shows differences between the repository’s Index and the HEAD commit.
Once staging is complete, you can Commit changes via the Commit View or by selecting the Working Tree root in the Repositories View and invoking the Commit command.
Advanced Staging
In addition to staging changes at file level, Git allows allows partial staging of changes to a file by enabling the staging of Hunks (groups of contiguous lines within a file).
Staging or unstaging hunks of modified files can be done in the Changes View or through the Index Editor dialog.
The Index Editor
By selecting a modified file and invoking the Index Editor (e.g., via Local | Index Editor), the Index Editor dialog displays a three-way diff view:
- Repository state (HEAD): Shown in the left pane.
- Index state: Shown in the center pane.
- Working Tree state: Shown in the right pane.
As with the Changes View, use the << and >> arrows or the x buttons to move change Hunks between views.
Additional Capabilities of the Index Editor
In addition to staging entire files and Hunks, the Index Editor allows:
- Staging individual lines: Right-click a line to stage it.
- Staging a selection of lines.
- Direct editing: Modify the file’s contents in the Index and the Working Tree areas, though the Repository area remains uneditable.
Note
- If a File is only partly staged (i.e., not all change Hunks are added to the Index) or if subsequent changes are made to the Index version, the Files View will show the file in both the Unstaged and Staged panes. This enables you to use the Changes View to see the relative differences between:
- The Working Tree and Index.
- The Index and HEAD.
- Editing the Working Tree and Index independently can result in changes in the Index not present in the Working Tree file. After committing changes from the Index, the Working Tree file may appear Modified.
- If not all changes in a Working Tree file are staged, the remaining changes will stay unstaged after creating a new commit.These residual changes can be added to a future commit.
Discarding Changes
Use Local | Discard (or the equivalent context menu option) to revert the contents of the selected files:
- Back to their Index state.
- Back to their repository state (HEAD). If the Working Tree is in a merging or rebasing state, this command can also be applied to the root of the Working Tree to exit the merging or rebasing state.