git-gui: Avoid unnecessary symbolic-ref call during checkout

diff --git a/lib/checkout_op.tcl b/lib/checkout_op.tcl
index 8c42ca8005c9d6ee1fdafe6b631ed075fc0093a1..40cc73a527374124be6539f0bfe81ddc54a1f227 100644 (file)
--- a/lib/checkout_op.tcl
+++ b/lib/checkout_op.tcl
@@ -385,22 +385,24 @@ method _after_readtree {} {
        set rn [string length $rh]
        if {[string equal -length $rn $rh $new_ref]} {
                set new_branch [string range $new_ref $rn end]
-               append log " to $new_branch"
-
-               if {[catch {
-                               git symbolic-ref -m $log HEAD $new_ref
-                       } err]} {
-                       _fatal $this $err
+               if {$is_detached || $current_branch ne $new_branch} {
+                       append log " to $new_branch"
+                       if {[catch {
+                                       git symbolic-ref -m $log HEAD $new_ref
+                               } err]} {
+                               _fatal $this $err
+                       }
+                       set current_branch $new_branch
+                       set is_detached 0
                }
-               set current_branch $new_branch
-               set is_detached 0
        } else {
-               append log " to $new_expr"
-
-               if {[catch {
-                               _detach_HEAD $log $new_hash
-                       } err]} {
-                       _fatal $this $err
+               if {$new_hash ne $HEAD} {
+                       append log " to $new_expr"
+                       if {[catch {
+                                       _detach_HEAD $log $new_hash
+                               } err]} {
+                               _fatal $this $err
+                       }
                }
                set current_branch HEAD
                set is_detached 1