git/diff.c, branch v2.14.3

Merge branch 'jk/write-in-full-fix' into maint

2017-10-23T05:37:22Z

Many codepaths did not diagnose write failures correctly when disks go full, due to their misuse of write_in_full() helper function, which have been corrected. * jk/write-in-full-fix: read_pack_header: handle signed/unsigned comparison in read result config: flip return value of store_write_*() notes-merge: use ssize_t for write_in_full() return value pkt-line: check write_in_full() errors against "< 0" convert less-trivial versions of "write_in_full() != len" avoid "write_in_full(fd, buf, len) != len" pattern get-tar-commit-id: check write_in_full() return against 0 config: avoid "write_in_full(fd, buf, len) < len" pattern

Merge branch 'rj/no-sign-compare' into maint

2017-10-23T05:20:18Z

Many codepaths have been updated to squelch -Wsign-compare warnings. * rj/no-sign-compare: ALLOC_GROW: avoid -Wsign-compare warnings cache.h: hex2chr() - avoid -Wsign-compare warnings commit-slab.h: avoid -Wsign-compare warnings git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings

Revert "color: check color.ui in git_default_config()"

2017-10-17T06:09:52Z

This reverts commit 136c8c8b8fa39f1315713248473dececf20f8fe7. That commit was trying to address a bug caused by 4c7f1819b3 (make color.ui default to 'auto', 2013-06-10), in which plumbing like diff-tree defaulted to "auto" color, but did not respect a "color.ui" directive to disable it. But it also meant that we started respecting "color.ui" set to "always". This was a known problem, but 4c7f1819b3 argued that nobody ought to be doing that. However, that turned out to be wrong, and we got a number of bug reports related to "add -p" regressing in v2.14.2. Let's revert 136c8c8b8, fixing the regression to "add -p". This leaves the problem from 4c7f1819b3 unfixed, but: 1. It's a pretty obscure problem in the first place. I only noticed it while working on the color code, and we haven't got a single bug report or complaint about it. 2. We can make a more moderate fix on top by respecting "never" but not "always" for plumbing commands. This is just the minimal fix to go back to the working state we had before v2.14.2. Note that this isn't a pure revert. We now have a test in t3701 which shows off the "add -p" regression. This can be flipped to success. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

ALLOC_GROW: avoid -Wsign-compare warnings

2017-09-22T04:21:11Z

Signed-off-by: Ramsay Jones Signed-off-by: Junio C Hamano

avoid "write_in_full(fd, buf, len) != len" pattern

2017-09-14T06:17:59Z

The return value of write_in_full() is either "-1", or the requested number of bytes[1]. If we make a partial write before seeing an error, we still return -1, not a partial value. This goes back to f6aa66cb95 (write_in_full: really write in full or return error on disk full., 2007-01-11). So checking anything except "was the return value negative" is pointless. And there are a couple of reasons not to do so: 1. It can do a funny signed/unsigned comparison. If your "len" is signed (e.g., a size_t) then the compiler will promote the "-1" to its unsigned variant. This works out for "!= len" (unless you really were trying to write the maximum size_t bytes), but is a bug if you check "< len" (an example of which was fixed recently in config.c). We should avoid promoting the mental model that you need to check the length at all, so that new sites are not tempted to copy us. 2. Checking for a negative value is shorter to type, especially when the length is an expression. 3. Linus says so. In d34cf19b89 (Clean up write_in_full() users, 2007-01-11), right after the write_in_full() semantics were changed, he wrote: I really wish every "write_in_full()" user would just check against "<0" now, but this fixes the nasty and stupid ones. Appeals to authority aside, this makes it clear that writing it this way does not have an intentional benefit. It's a historical curiosity that we never bothered to clean up (and which was undoubtedly cargo-culted into new sites). So let's convert these obviously-correct cases (this includes write_str_in_full(), which is just a wrapper for write_in_full()). [1] A careful reader may notice there is one way that write_in_full() can return a different value. If we ask write() to write N bytes and get a return value that is _larger_ than N, we could return a larger total. But besides the fact that this would imply a totally broken version of write(), it would already invoke undefined behavior. Our internal remaining counter is an unsigned size_t, which means that subtracting too many byte will wrap it around to a very large number. So we'll instantly begin reading off the end of the buffer, trying to write gigabytes (or petabytes) of data. Signed-off-by: Jeff King Reviewed-by: Jonathan Nieder Signed-off-by: Junio C Hamano

color: check color.ui in git_default_config()

2017-07-13T19:42:51Z

Back in prehistoric times, our decision on whether or not to show color by default relied on using a config callback that either did or didn't load color config like color.diff. When we introduced color.ui, we put it in the same boat: commands had to manually respect it by using git_color_config() or its git_color_default_config() convenience wrapper. But in 4c7f1819b (make color.ui default to 'auto', 2013-06-10), that changed. Since then, we default color.ui to auto in all programs, meaning that even plumbing commands like "git diff-tree --pretty" might colorize the output. Nobody seems to have complained in the intervening years, presumably because the "is stdout a tty" check does a good job of catching the right cases. But that leaves an interesting curiosity: color.ui defaults to auto even in plumbing, but you can't actually _disable_ the color via config. So if you really hate color and set "color.ui" to false, diff-tree will still show color (but porcelain like git-diff won't). Nobody noticed that either, probably because very few people disable color. One could argue that the plumbing should _always_ disable color unless an explicit --color option is given on the command line. But in practice, this creates a lot of complications for scripts which do want plumbing to show user-visible output. They can't just pass "--color" blindly; they need to check the user's config and decide what to send. Given that nobody has complained about the current behavior, let's assume it's a good path, and follow it to its conclusion: supporting color.ui everywhere. Note that you can create havoc by setting color.ui=always in your config, but that's more or less already the case. We could disallow it entirely, but it is handy for one-offs like: git -c color.ui=always foo >not-a-tty when "foo" does not take a --color option itself. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'rs/use-div-round-up'

2017-07-12T22:18:23Z

Code cleanup. * rs/use-div-round-up: use DIV_ROUND_UP

use DIV_ROUND_UP

2017-07-10T21:24:36Z

Convert code that divides and rounds up to use DIV_ROUND_UP to make the intent clearer and reduce the number of magic constants. Signed-off-by: Rene Scharfe Reviewed-by: Jeff King Signed-off-by: Junio C Hamano

Merge branch 'ab/free-and-null'

2017-06-24T21:28:41Z

A common pattern to free a piece of memory and assign NULL to the pointer that used to point at it has been replaced with a new FREE_AND_NULL() macro. * ab/free-and-null: *.[ch] refactoring: make use of the FREE_AND_NULL() macro coccinelle: make use of the "expression" FREE_AND_NULL() rule coccinelle: add a rule to make "expression" code use FREE_AND_NULL() coccinelle: make use of the "type" FREE_AND_NULL() rule coccinelle: add a rule to make "type" code use FREE_AND_NULL() git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL

Merge branch 'bw/config-h'

2017-06-24T21:28:41Z

Fix configuration codepath to pay proper attention to commondir that is used in multi-worktree situation, and isolate config API into its own header file. * bw/config-h: config: don't implicitly use gitdir or commondir config: respect commondir setup: teach discover_git_directory to respect the commondir config: don't include config.h by default config: remove git_config_iter config: create config.h