[PATCH] git gui: show diffs with a minimum of 1 context line

[Clemens Buchacher <drizzd@aon.at>]

git apply does not handle diffs without context correctly. Configuring git
gui to show zero context lines therefore breaks staging.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
---

In reply to this patch I will send a first attempt at fixing this problem
instead of avoiding it. There does not seem to be a straightforward
solution, however, so this should hide the bug for now.

 git-gui/git-gui.sh     |    2 +-
 git-gui/lib/diff.tcl   |    2 +-
 git-gui/lib/option.tcl |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/git-gui/git-gui.sh b/git-gui/git-gui.sh
index ad65aaa..86402d4 100755
--- a/git-gui/git-gui.sh
+++ b/git-gui/git-gui.sh
@@ -1932,7 +1932,7 @@ proc show_more_context {} {
 
 proc show_less_context {} {
 	global repo_config
-	if {$repo_config(gui.diffcontext) >= 1} {
+	if {$repo_config(gui.diffcontext) > 1} {
 		incr repo_config(gui.diffcontext) -1
 		reshow_diff
 	}
diff --git a/git-gui/lib/diff.tcl b/git-gui/lib/diff.tcl
index 52b79e4..4a7138b 100644
--- a/git-gui/lib/diff.tcl
+++ b/git-gui/lib/diff.tcl
@@ -175,7 +175,7 @@ proc show_diff {path w {lno {}} {scroll_pos {}}} {
 
 	lappend cmd -p
 	lappend cmd --no-color
-	if {$repo_config(gui.diffcontext) >= 0} {
+	if {$repo_config(gui.diffcontext) >= 1} {
 		lappend cmd "-U$repo_config(gui.diffcontext)"
 	}
 	if {$w eq $ui_index} {
diff --git a/git-gui/lib/option.tcl b/git-gui/lib/option.tcl
index ffb3f00..5e1346e 100644
--- a/git-gui/lib/option.tcl
+++ b/git-gui/lib/option.tcl
@@ -125,7 +125,7 @@ proc do_options {} {
 		{b gui.matchtrackingbranch {mc "Match Tracking Branches"}}
 		{b gui.fastcopyblame {mc "Blame Copy Only On Changed Files"}}
 		{i-20..200 gui.copyblamethreshold {mc "Minimum Letters To Blame Copy On"}}
-		{i-0..99 gui.diffcontext {mc "Number of Diff Context Lines"}}
+		{i-1..99 gui.diffcontext {mc "Number of Diff Context Lines"}}
 		{i-0..99 gui.commitmsgwidth {mc "Commit Message Text Width"}}
 		{t gui.newbranchtemplate {mc "New Branch Name Template"}}
 		} {
-- 
1.6.0