We have operations to "extract" and "update" a "struct tree_desc", but we
only used them in tree-diff.c and they were static to that file.
But other tree traversal functions can use them to their advantage
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Avoid asking for zero bytes when that change simplifies overall
logic. Later we would change the wrapper to ask for 1 byte on
platforms that return NULL for zero byte request.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This makes the tree diff functionality independent of the "git-diff-tree"
program, by splitting the core functionality up into a library file.
This will be needed for when we teach git-rev-list to only follow a
specified set of pathnames, rather than the global revision history.
Most of it is a fairly straightforward code move, but it also involves
some calling convention cleanup, and moving some of the static variables
from diff-tree.c into the options structure.
The actual tree change callback routines also become paramterized by the
diff_options structure, allowing the library functionality to do something
else than just show the diff on stdout.
Right now the only user of this functionality remains git-diff-tree
itself.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
