Fix bug: invalid empty PBM image when G3 input in empty

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@3152 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 7 insertions, 4 deletions

diff --git a/converter/pbm/g3topbm.c b/converter/pbm/g3topbm.c
index 0b75903e..1ffa3893 100644
--- a/converter/pbm/g3topbm.c
+++ b/converter/pbm/g3topbm.c
@@ -788,7 +788,6 @@ main(int argc, const char * argv[]) {
     struct BitStream bitStream;
     unsigned int rows, cols;
     unsigned char ** packedBits;
-    int row;
 
     pm_proginit(&argc, argv);
 
@@ -814,9 +813,13 @@ main(int argc, const char * argv[]) {
 
     pm_close(ifP);
 
-    pbm_writepbminit(stdout, cols, rows, 0);
-    for (row = 0; row < rows; ++row)
-        pbm_writepbmrow_packed(stdout, packedBits[row], cols, 0);
+    if (cols > 0 && rows > 0) {
+        unsigned int row;
+        pbm_writepbminit(stdout, cols, rows, 0);
+        for (row = 0; row < rows; ++row)
+            pbm_writepbmrow_packed(stdout, packedBits[row], cols, 0);
+    } else
+        pm_error("No image data in input");
 
     pm_close(stdout);