In Unix PuTTYgen, existing SSH-1 key comments were coming out as "(null)"

for operations not performing decryption (e.g., "puttygen rsa1.ppk -L")
(A use for r6434 -- wasn't expecting that.)

[originally from svn r6436]
[r6434 == c14f259ba2]

cmdgen.c

@@ -690,8 +690,8 @@ int main(int argc, char **argv)
 		char *blob;
 		int n, l, bloblen;
 
-		ret = rsakey_pubblob(&infilename, &vblob, &bloblen, NULL,
-				     &error);
+		ret = rsakey_pubblob(&infilename, &vblob, &bloblen,
+				     &origcomment, &error);
 		blob = (char *)vblob;
 
 		n = 4;		       /* skip modulus bits */
@@ -709,7 +709,7 @@ int main(int argc, char **argv)
 		    } else
 			n += l;
 		}
-		ssh1key->comment = NULL;
+		ssh1key->comment = dupstr(origcomment);
 		ssh1key->private_exponent = NULL;
 	    } else {
 		ret = loadrsakey(&infilename, ssh1key, passphrase, &error);