Bugfix: smb_addcrc() no longer tries to malloc or read the CRC history file if

the length is 0.
smb_addcrc() now verifies the file is evenly divisible by 4 bytes (the size of
a 32-bit CRC record).

src/smblib/smblib.c

@@ -1248,12 +1248,13 @@ int SMBCALL smb_addcrc(smb_t* smb, ulong crc)
 	}
 
 	length=filelength(file);
-	if(length<0L) {
+	if(length<0L || length%sizeof(long)) {
 		close(file);
 		sprintf(smb->last_error,"invalid file length: %ld", length);
 		return(SMB_ERR_FILE_LEN); 
 	}
 
+	if(length!=0) {
 		if((buf=(ulong*)MALLOC(length))==NULL) {
 			close(file);
 			sprintf(smb->last_error
@@ -1288,8 +1289,9 @@ int SMBCALL smb_addcrc(smb_t* smb, ulong crc)
 			lseek(file,0L,SEEK_SET);
 			write(file,buf+(length-newlen),newlen); 
 		}
-	wr=write(file,&crc,sizeof(crc));	/* Write to the end */
 		FREE(buf);
+	}
+	wr=write(file,&crc,sizeof(crc));	/* Write to the end */
 	close(file);
 
 	if(wr!=sizeof(crc)) {