https://github.com/ImageMagick/ImageMagick/issues/1612

diff --git a/coders/pnm.c b/coders/pnm.c
index f6f69bf83c22188cc8c01b86e45d3ce565a2d954..a54bc60c33d14525e32541e3944933c775defa94 100644 (file)
--- a/coders/pnm.c
+++ b/coders/pnm.c
@@ -1826,7 +1826,7 @@ static MagickBooleanType WritePNMImage(const ImageInfo *image_info,Image *image,
             extent=(size_t) count;
             (void) strncpy((char *) q,buffer,extent);
             q+=extent;
-            if ((q-pixels+extent+1) >= sizeof(pixels))
+            if ((q-pixels+extent+2) >= sizeof(pixels))
               {
                 *q++='\n';
                 (void) WriteBlob(image,q-pixels,pixels);
@@ -1901,7 +1901,7 @@ static MagickBooleanType WritePNMImage(const ImageInfo *image_info,Image *image,
             extent=(size_t) count;
             (void) strncpy((char *) q,buffer,extent);
             q+=extent;
-            if ((q-pixels+extent+1) >= sizeof(pixels))
+            if ((q-pixels+extent+2) >= sizeof(pixels))
               {
                 *q++='\n';
                 (void) WriteBlob(image,q-pixels,pixels);