Merge branch 'master' of github.com:git/git

* 'master' of github.com:git/git: (397 commits)
  Git 2.33-rc0
  The seventh batch
  ci/install-dependencies: handle "sparse" job package installs
  ci: run "apt-get update" before "apt-get install"
  cache-tree: prefetch in partial clone read-tree
  unpack-trees: refactor prefetching code
  pack-bitmap: check pack validity when opening bitmap
  bundle tests: use test_cmp instead of grep
  bundle tests: use ">file" not ": >file"
  The sixth batch
  doc: pull: fix rebase=false documentation
  pack-bitmap: clarify comment in filter_bitmap_exclude_type()
  doc: clarify description of 'submodule.recurse'
  doc/git-config: simplify "override" advice for FILES section
  doc/git-config: clarify GIT_CONFIG environment variable
  doc/git-config: explain --file instead of referring to GIT_CONFIG
  t0000: fix test if run with TEST_OUTPUT_DIRECTORY
  multi-pack-index: fix potential segfault without sub-command
  refs/debug: quote prefix
  t0000: clear GIT_SKIP_TESTS before running sub-tests
  ...

1 files changed, 22 insertions, 9 deletions

diff --git a/xdiff-interface.h b/xdiff-interface.h
index 93df26900c..4301a7eef2 100644
--- a/xdiff-interface.h
+++ b/xdiff-interface.h
@@ -11,7 +11,28 @@
  */
 #define MAX_XDIFF_SIZE (1024UL * 1024 * 1023)
 
-typedef void (*xdiff_emit_line_fn)(void *, char *, unsigned long);
+/**
+ * The `xdiff_emit_line_fn` function can return 1 to abort early, or 0
+ * to continue processing. Note that doing so is an all-or-nothing
+ * affair, as returning 1 will return all the way to the top-level,
+ * e.g. the xdi_diff_outf() call to generate the diff.
+ *
+ * Thus returning 1 means you won't be getting any more diff lines. If
+ * you need something in-between those two options you'll to use
+ * `xdl_emit_hunk_consume_func_t` and implement your own version of
+ * xdl_emit_diff().
+ *
+ * We may extend the interface in the future to understand other more
+ * granular return values. While you should return 1 to exit early,
+ * doing so will currently make your early return indistinguishable
+ * from an error internal to xdiff, xdiff itself will see that
+ * non-zero return and translate it to -1.
+ *
+ * See "diff_grep" in diffcore-pickaxe.c for a trick to work around
+ * this, i.e. using the "consume_callback_data" to note the desired
+ * early return.
+ */
+typedef int (*xdiff_emit_line_fn)(void *, char *, unsigned long);
 typedef void (*xdiff_emit_hunk_fn)(void *data,
 				   long old_begin, long old_nr,
 				   long new_begin, long new_nr,
@@ -33,14 +54,6 @@ int git_xmerge_config(const char *var, const char *value, void *cb);
 extern int git_xmerge_style;
 
 /*
- * Can be used as a no-op hunk_fn for xdi_diff_outf(), since a NULL
- * one just sends the hunk line to the line_fn callback).
- */
-void discard_hunk_line(void *priv,
-		       long ob, long on, long nb, long nn,
-		       const char *func, long funclen);
-
-/*
  * Compare the strings l1 with l2 which are of size s1 and s2 respectively.
  * Returns 1 if the strings are deemed equal, 0 otherwise.
  * The `flags` given as XDF_WHITESPACE_FLAGS determine how white spaces