Merge branch 'en/rename-directory-detection'

Rename detection logic in "diff" family that is used in "merge" has
learned to guess when all of x/a, x/b and x/c have moved to z/a,
z/b and z/c, it is likely that x/d added in the meantime would also
want to move to z/d by taking the hint that the entire directory
'x' moved to 'z'.  A bug causing dirty files involved in a rename
to be overwritten during merge has also been fixed as part of this
work.

* en/rename-directory-detection: (29 commits)
  merge-recursive: ensure we write updates for directory-renamed file
  merge-recursive: avoid spurious rename/rename conflict from dir renames
  directory rename detection: new testcases showcasing a pair of bugs
  merge-recursive: fix remaining directory rename + dirty overwrite cases
  merge-recursive: fix overwriting dirty files involved in renames
  merge-recursive: avoid clobbering untracked files with directory renames
  merge-recursive: apply necessary modifications for directory renames
  merge-recursive: when comparing files, don't include trees
  merge-recursive: check for file level conflicts then get new name
  merge-recursive: add computation of collisions due to dir rename & merging
  merge-recursive: check for directory level conflicts
  merge-recursive: add get_directory_renames()
  merge-recursive: make a helper function for cleanup for handle_renames
  merge-recursive: split out code for determining diff_filepairs
  merge-recursive: make !o->detect_rename codepath more obvious
  merge-recursive: fix leaks of allocated renames and diff_filepairs
  merge-recursive: introduce new functions to handle rename logic
  merge-recursive: move the get_renames() function
  directory rename detection: tests for handling overwriting dirty files
  directory rename detection: tests for handling overwriting untracked files
  ...

1 files changed, 16 insertions, 0 deletions

diff --git a/strbuf.h b/strbuf.h
index e6cae5f..652f173 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -1,6 +1,8 @@
 #ifndef STRBUF_H
 #define STRBUF_H
 
+struct string_list;
+
 /**
  * strbuf's are meant to be used with all the usual C string and memory
  * APIs. Given that the length of the buffer is known, it's often better to
@@ -531,6 +533,20 @@ static inline struct strbuf **strbuf_split(const struct strbuf *sb,
 	return strbuf_split_max(sb, terminator, 0);
 }
 
+/*
+ * Adds all strings of a string list to the strbuf, separated by the given
+ * separator.  For example, if sep is
+ *   ', '
+ * and slist contains
+ *   ['element1', 'element2', ..., 'elementN'],
+ * then write:
+ *   'element1, element2, ..., elementN'
+ * to str.  If only one element, just write "element1" to str.
+ */
+extern void strbuf_add_separated_string_list(struct strbuf *str,
+					     const char *sep,
+					     struct string_list *slist);
+
 /**
  * Free a NULL-terminated list of strbufs (for example, the return
  * values of the strbuf_split*() functions).