From 31c9d1a80257d5436e7d0af591886c407fc67c38 Mon Sep 17 00:00:00 2001
From: tTh <tth@konrad.lan>
Date: Thu, 25 Jun 2026 06:29:55 +0200
Subject: [PATCH] add a molly-guard

---
 Modules/spitpgm.f90 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Modules/spitpgm.f90 b/Modules/spitpgm.f90
index f573bdc..480ba81 100644
--- a/Modules/spitpgm.f90
+++ b/Modules/spitpgm.f90
@@ -49,7 +49,7 @@ end subroutine
 !-------------------------------------------------------------------
 !-
 !     16 bits - 65535 levels portable grey map file
-!     no data conversion except upper clippin.
+!     no data conversion except upper clipping.
 !-
 subroutine spit_as_pgm_16(pic, fname)
     integer, intent(in), dimension (:,:)  ::  pic
@@ -69,6 +69,7 @@ subroutine spit_as_pgm_16(pic, fname)
       do ix=1, ubound(pic, 1)
         foo = pic(ix, iy)
         if (foo .GT. 65535)  foo = 65535
+        if (foo .LT.     0)  foo = 0
         write(io, "(i0)") foo
       enddo
     enddo
@@ -96,6 +97,7 @@ subroutine spit_as_pgm_8(pic, fname)
       do ix=1, ubound(pic, 1)
         foo = pic(ix, iy)
         if (foo .GT. 255)  foo = 255
+        if (foo .LT.   0)  foo = 0
         write(io, "(i0)") foo
       enddo
     enddo