kernel/git - git - PowerEL Git System

Tree: 63267de2ac

Author	SHA1	Message	Date
Linus Torvalds	48fb7deb5b	Fix big left-shifts of unsigned char Shifting 'unsigned char' or 'unsigned short' left can result in sign extension errors, since the C integer promotion rules means that the unsigned char/short will get implicitly promoted to a signed 'int' due to the shift (or due to other operations). This normally doesn't matter, but if you shift things up sufficiently, it will now set the sign bit in 'int', and a subsequent cast to a bigger type (eg 'long' or 'unsigned long') will now sign-extend the value despite the original expression being unsigned. One example of this would be something like unsigned long size; unsigned char c; size += c << 24; where despite all the variables being unsigned, 'c << 24' ends up being a signed entity, and will get sign-extended when then doing the addition in an 'unsigned long' type. Since git uses 'unsigned char' pointers extensively, we actually have this bug in a couple of places. I may have missed some, but this is the result of looking at git grep '[^0-9 ][ ]<<[ ][a-z]' -- '.c' '.h' git grep '<<[ ]24' which catches at least the common byte cases (shifting variables by a variable amount, and shifting by 24 bits). I also grepped for just 'unsigned char' variables in general, and converted the ones that most obviously ended up getting implicitly cast immediately anyway (eg hash_name(), encode_85()). In addition to just avoiding 'unsigned char', this patch also tries to use a common idiom for the delta header size thing. We had three different variations on it: "& 0x7fUL" in one place (getting the sign extension right), and "& ~0x80" and "& 0x7f" in two other places (not getting it right). Apart from making them all just avoid using "unsigned char" at all, I also unified them to then use a simple "& 0x7f". I considered making a sparse extension which warns about doing implicit casts from unsigned types to signed types, but it gets rather complex very quickly, so this is just a hack. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
Jerald Fitzjerald	86d14e1b1d	decode_85(): fix missing return. When the function detected an invalid base85 sequence, it issued an error message but forgot to return error status at that point and kept going. Signed-off-by: Jerald Fitzjerald <jfj@freemail.gr> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Jim Meyering	f981577202	(encode_85, decode_85): Mark source buffer pointer as "const". Signed-off-by: Jim Meyering <jim@meyering.net> Signed-off-by: Junio C Hamano <junkio@cox.net>	18 years ago
Nicolas Pitre	addaacab07	improve base85 generated assembly code This code is arguably pretty hot, if you use binary patches of course. This patch helps gcc generate both smaller and faster code especially in the error free path. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Junio C Hamano	0660626caf	binary diff: further updates. This updates the user interface and generated diff data format. * "diff --binary" is used to signal that we want an e-mailable binary patch. It implies --full-index and -p. * "apply --allow-binary-replacement" acquired a short synonym "apply --binary". * After the "GIT binary patch\n" header line there is a token to record which binary patch mechanism was used, so that we can extend it later. Currently there are two mechanisms defined: "literal" and "delta". The former records the deflated postimage and the latter records the deflated delta from the preimage to postimage. For purely implementation convenience, I added the deflated length after these "literal/delta" tokens (otherwise the decoding side needs to guess and reallocate the buffer while inflating). Improvement patches are very welcomed. Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago