Description of problem: compiler warning: call ... will always overflow destination buffer. indeed, there is a trivial bug in the code, no space is reserved for trailing \0. patch to fix: --- libytnef-1.5/ytnef.c 2004-08-26 17:09:05.000000000 +0000 +++ libytnef-1.5/ytnef.c 2012-06-08 19:34:07.826123387 +0000 @@ -1327,7 +1327,7 @@ ULONG compressedSize, uncompressedSize, magic, crc32; comp_Prebuf.size = strlen(RTF_PREBUF); - comp_Prebuf.data = calloc(comp_Prebuf.size, 1); + comp_Prebuf.data = calloc(comp_Prebuf.size+1, 1); strcpy(comp_Prebuf.data, RTF_PREBUF); src = p->data; Version-Release number of selected component (if applicable): libytnef-1.5-7.fc17