User guide

Diff and staging Partly available

The diff shows the changes of one file. Read it on the side you choose, stage or unstage whole chunks or single lines, and pick one of two layouts. The same view shows the changes in the Working Copy and the changes of a commit opened from History.

Staged and Unstaged#

The Staged | Unstaged selector in the diff header chooses the side you look at:

• Staged shows the changes already staged for the next commit.
• Unstaged shows the changes you have not staged yet.

The header shows the file path and the change count, such as +5 −1. Below it, a summary line gives the totals, for example 2 chunks, 3 insertions, 4 deletions.

Stage and unstage chunks#

A chunk is a block of changed lines. Each chunk starts with a @@ header line, and its buttons sit on that line:

• Discard Chunk throws away the chunk's changes. Click it, and the header asks Discard this chunk? with Discard and Cancel buttons. Only the Unstaged side can discard. On the Staged side the button is dimmed and does nothing.
• Stage Chunk stages the chunk. On the Staged side, the button reads Unstage Chunk and unstages it.

To stage a chunk:

1. Select the file in the Working Copy.
2. Open the Unstaged side.
3. Click Stage Chunk on the chunk's header line.

Stage single lines#

Stage part of a chunk by choosing lines:

1. Open the Unstaged side of the file.
2. Choose lines in one of two ways. Tick the checkbox in the gutter of each line, or press Ctrl+Shift+V (⇧⌘V on macOS) to start a visual selection at the cursor, then move the cursor.
3. Press Ctrl+Shift+S (⇧⌘S on macOS) to stage the selected lines.

On the Staged side, press Ctrl+Shift+I (⇧⌘I on macOS) to unstage the selected lines.

Half-staged pairs#

A removed line and the added line that replaces it form a pair. If you stage only one side of a pair, the index can end up without the old line and without the new one, and the file may not compile. When your selection splits a pair, the view shows the warning Half-staged −/+ pair: the index would lose both the old and the new line, and may not compile. Select the other side too, or stage the whole chunk.

Staging uses the exact diff#

Staging always works on the exact diff that Git computes for the file. The lines you stage and the lines you leave out always add up to the whole change: the staged part plus the unstaged part equals the full change.

Ignoring whitespace#

Ignoring whitespace only filters what the diff shows. It never changes what gets staged, because staging still uses the exact diff.

Diff algorithm#

The diff uses Git's histogram algorithm, the one that git diff --histogram uses.

Unified and Split layouts#

Use the Unified | Split selector in the diff header to switch layouts. Unified is the default.

• Unified shows removed and added lines one after another, in one column.
• Split shows the old side on the left and the new side on the right. The two sides are paired one row at a time: each row holds one line of the old side and one line of the new side. Where a side has no line for a row, that side stays empty, with no line number and no marker. Each side's gutter marks only its own line.

Each line shows its line number. Both layouts scroll sideways (in Split, both sides together): use a horizontal wheel or a trackpad gesture.

The layout you choose is saved for your user account as gitmaster.diffLayout in ~/.gitconfig. The Working Copy diff and the commit diff share the choice, so changing it in one changes both. A repository can override it with git config gitmaster.diffLayout split. If the key is missing or has another value, Unified is used. See Configuration.

Binary files#

A binary file shows the notice Binary file (n/a) in the Working Copy diff, instead of lines. In the stacked diff of a commit, the notice is Binary file: its contents are not shown.

Stacked diff of a commit#

Open a commit from History, then click a file in its file list. GitMaster shows the diff of every file in the commit in one continuous view, in the order of the file list, and scrolls to the file you clicked.

Each file has a header with its status letter, its path (a renamed file shows old → new), and its + and − counts. The header above the files shows N files and the Unified | Split selector, which applies to every file.

A file with nothing to show as lines has a notice in place of the lines. This applies to a binary file, a renamed file with no text changes, a file whose mode changed, and an empty file.

Two limits apply:

• A file with more than 5,000 lines shows the line and N more lines, not shown.
• After the first 200 files, the last line reads and N more files, not shown.

The stacked commit diff is read-only. It has no stage or discard buttons. Press Esc to return to the commit.

Word-level highlighting#

The changed words inside a line are highlighted on the visible chunks.

Moved code#

Lines that moved from one place to another are marked as moved, not as removed and added.

Syntax highlighting#

Diff lines are colored by the syntax of their language.

Keyboard in the diff views#

The diff views have no single-letter shortcuts. Every letter shortcut uses Ctrl+Shift (⇧⌘ on macOS). The keyboard shortcuts reference lists every shortcut in the app.

Working Copy diff#

Stacked commit diff#