Make pbm_cleanrowend_packed() work with zero-width images

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@2490 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 7 insertions, 6 deletions

diff --git a/lib/libpbm2.c b/lib/libpbm2.c
index e12b1e33..503fd6c9 100644
--- a/lib/libpbm2.c
+++ b/lib/libpbm2.c
@@ -268,15 +268,16 @@ pbm_cleanrowend_packed(unsigned char * const packedBits,
 /*----------------------------------------------------------------------------
   Set fractional "don't care" bits at end of row to zero.
 ----------------------------------------------------------------------------*/
-    unsigned int const last = pbm_packed_bytes(cols) - 1;
     unsigned int const bitsPerChar = 8;
 
-    assert(cols > 0);
-
     if (cols % bitsPerChar > 0) {
-            packedBits[last] >>= bitsPerChar - cols % bitsPerChar;
-            packedBits[last] <<= bitsPerChar - cols % bitsPerChar;
-        }
+        unsigned int const last = pbm_packed_bytes(cols) - 1;
+
+        assert(pbm_packed_bytes(cols) > 0);
+
+        packedBits[last] >>= bitsPerChar - cols % bitsPerChar;
+        packedBits[last] <<= bitsPerChar - cols % bitsPerChar;
+    }
 }