The Index
The Index is an intermediate cache for preparing a commit by identifying which file changes (including new and deleted files) you’d like to include in your next commit.
With SmartGit, you have the option to view the details of the Index, or, if you prefer simplicity, SmartGit can automatically manage the Index for you, allowing you to ignore its presence completely - it’s all up to you.
The Stage command allows you to save a file’s content from your working tree into the Index. If you stage a file that was previously version-controlled but is now missing in the working tree, it will be marked for removal. If you select a file with Index changes, invoking Commit will give you the option to commit all staged changes.
If you have staged some file changes and later modify the working tree file again, you can use the Discard command to either revert the working tree file’s content to the staged changes stored in the Index or to the file content stored in the repository (HEAD).
When unstaging previously staged changes, the staged changes will be moved back to the working tree, if the latter hasn’t been modified in the meantime; otherwise, the staged changes will be lost. Either way, the Index will be reverted to the HEAD file content.
Changes view
The Changes view of the SmartGit Working Tree window can show the differences between the HEAD and the Index, or between the Index and the working tree state of the selected file. You can switch between both views either by clicking the left HEAD button or the right Working Tree button. The detected and expected line separators are shown in the Changes view title. Individual change hunks or inner-line changes can be staged and unstaged there (if the line separators are not mixed).
Index Editor
The Index Editor shows a three-pane-view of HEAD, the Index, and the Working Tree. The Index and the Working Tree states of a file can be edited freely, for example, to add further modifications to the Index that are not available in the Working Tree.