git-gui: Don't nice git blame on MSYS as nice is not supported

Johannes Sixt reported that MinGW/MSYS does not have a nice.exe to
drop the priority of a child process when it gets spawned.  So we
have to avoid trying to start `git blame` through nice when we are
on Windows and do not have Cygwin available to us.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/lib/blame.tcl b/lib/blame.tcl
index 076233c3c33a1a39a1c5cb5727edfe240e618607..b5236548152043c5ec29997a791f5a51fa3f56cb 100644 (file)
--- a/lib/blame.tcl
+++ b/lib/blame.tcl
@@ -487,7 +487,11 @@ method _read_file {fd jump} {
 } ifdeleted { catch {close $fd} }
 
 method _exec_blame {cur_w cur_d options cur_s} {
-       set cmd [list nice git blame]
+       set cmd [list]
+       if {![is_Windows] || [is_Cygwin]} {
+               lappend cmd nice
+       }
+       lappend cmd git blame
        set cmd [concat $cmd $options]
        lappend cmd --incremental
        if {$commit eq {}} {