[gimp] Fixed modulo function which affected 'random' procedure. (See bug #647541)

[Kevin Cozens <kcozens src gnome org>]

commit f1c20cb165d2db8702a9f6ba61d32b590ae88979
Author: Kevin Cozens <kcozens cvs gnome org>
Date:   Wed Apr 13 13:38:04 2011 -0400

    Fixed modulo function which affected 'random' procedure. (See bug #647541)

 plug-ins/script-fu/tinyscheme/scheme.c |   14 ++++++++------
 1 files changed, 8 insertions(+), 6 deletions(-)
---
diff --git a/plug-ins/script-fu/tinyscheme/scheme.c b/plug-ins/script-fu/tinyscheme/scheme.c
index 6571405..d9aa2cd 100644
--- a/plug-ins/script-fu/tinyscheme/scheme.c
+++ b/plug-ins/script-fu/tinyscheme/scheme.c
@@ -516,12 +516,14 @@ static num num_mod(num a, num b) {
  e1=num_ivalue(a);
  e2=num_ivalue(b);
  res=e1%e2;
- if(res*e2<0) {    /* modulo should have same sign as second operand */
-     e2=labs(e2);
-     if(res>0) {
-          res-=e2;
-     } else {
-          res+=e2;
+ /* modulo should have same sign as second operand */
+ if (res > 0) {
+     if (e2 < 0) {
+          res*=-1L;
+     }
+ } else {
+     if (e2 > 0) {
+          res*=-1L;
      }
  }
  ret.value.ivalue=res;