[PATCH] diff.tcl: fixed alignment of tabs in git-gui diff by using spaces

From

CGChris Idema via GitGitGadget <gitgitgadget@gmail.com>

Date

Jan 26, 2026, 10:45 UTC

Message-ID

<pull.2179.git.git.1769424301394.gitgitgadget@gmail.com>

From: Chris Idema <github_chris_idema@proton.me>

Signed-off-by: Chris Idema <github_chris_idema@proton.me>
---
    diff.tcl: Fixed alignment of tabs in git-gui diff by using spaces.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2179%2FChrisIdema%2Ffix-gitgui-diff-tab-alignment-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2179/ChrisIdema/fix-gitgui-diff-tab-alignment-v1
Pull-Request: https://github.com/git/git/pull/2179

 git-gui/lib/diff.tcl | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/git-gui/lib/diff.tcl b/git-gui/lib/diff.tcl
index 442737ba4f..2e13f8c776 100644
--- a/git-gui/lib/diff.tcl
+++ b/git-gui/lib/diff.tcl
@@ -12,6 +12,27 @@ proc apply_tab_size {{firsttab {}}} {
 	}
 }
 
+proc expand_tabs {line {startcol -1}} {
+	# startcol set to -1, because in preview the lines start with a '+', '-', or ' '
+	global repo_config
+
+	set col $startcol
+	set out ""
+
+	foreach char [split $line ""] {
+		if {$char eq "\t"} {
+			set spaces [expr {$repo_config(gui.tabsize) - ($col % $repo_config(gui.tabsize))}]
+			append out [string repeat " " $spaces]
+			incr col $spaces
+		} else {
+			append out $char
+			incr col
+		}
+	}
+
+	return $out
+}
+
 proc clear_diff {} {
 	global ui_diff current_diff_path current_diff_header
 	global ui_index ui_workdir
@@ -495,7 +516,9 @@ proc read_diff {fd conflict_size cont_info} {
 			}
 		}
 		set mark [$ui_diff index "end - 1 line linestart"]
-		$ui_diff insert end $line $tags
+		set line [expand_tabs $line]
+		$ui_diff insert end "$line" $tags
+
 		if {[string index $line end] eq "\r"} {
 			$ui_diff tag add d_cr {end - 2c}
 		}

base-commit: 1faf5b085a171f9ba9a6d7a446e0de16acccb1dc

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