regresssion update failures/diffs

Signed-off-by: James Cherry <cherry@parallaxsw.com>

test/regression.tcl

@@ -177,7 +177,6 @@ proc run_tests {} {
     }
   }
   write_failure_file
-  write_diff_file
 }
 
 proc run_test { test } {
@@ -268,6 +267,8 @@ proc run_tests_parallel {} {
         vwait reg_parallel_job_done
       }
     }
+    # update results/failures and results/diffs
+    write_failure_file
   }
 }
 
@@ -434,23 +435,23 @@ proc test_failed { test reason } {
 }
 
 proc write_failure_file {} {
-  global failure_file failed_tests
+  global failure_file failed_tests failed_tests_summery
+  global diff_file diff_options
 
-  set ch [open $failure_file "w"]
+  set fail_ch [open $failure_file "a"]
   foreach test $failed_tests {
-    puts $ch $test
-  }
-  close $ch
-}
+    if { ![info exists failed_tests_summery($test)] } {
+      puts $fail_ch $test
 
-proc write_diff_file {} {
-  global diff_file diff_options failed_tests
+      # Append diff to results/diffs
+      set log_file [test_log_file $test]
+      set ok_file [test_ok_file $test]
+      catch [concat exec diff $diff_options $ok_file $log_file >> $diff_file]
 
-  foreach test $failed_tests {
-    set log_file [test_log_file $test]
-    set ok_file [test_ok_file $test]
-    catch [concat exec diff $diff_options $ok_file $log_file >> $diff_file]
+      set failed_tests_summery($test) 1
+    }
   }
+  close $fail_ch
 }
 
 # Error messages can be found in "valgrind/memcheck/mc_errcontext.c".