Merge branch 'pk/rebase-in-c-3-acts'

Rewrite "git rebase" in C.

* pk/rebase-in-c-3-acts:
builtin rebase: stop if `git am` is in progress
builtin rebase: actions require a rebase in progress
builtin rebase: support --edit-todo and --show-current-patch
builtin rebase: support --quit
builtin rebase: support --abort
builtin rebase: support --skip
builtin rebase: support --continue

diff --cc builtin/rebase.c
index 71367c8530e77035fe89ddfee8fcef0d77eaced0,2165656ae24a872a5faebc9fcac470aa933a194d..13084082776d6a72da0d1fe44cd2ad8163e07cb4
--- 1/builtin/rebase.c
--- 2/builtin/rebase.c
+++ b/builtin/rebase.c
@@@ -21,7 -21,7 +21,8 @@@
  #include "diff.h"
  #include "wt-status.h"
  #include "revision.h"
 +#include "commit-reach.h"
+ #include "rerere.h"
  
  static char const * const builtin_rebase_usage[] = {
        N_("git rebase [-i] [options] [--exec <cmd>] [--onto <newbase>] "

diff --cc strbuf.c
Simple merge

diff --cc strbuf.h
index 9981f782b2573c1a4360879e03884ec753999aec,b7aea8a9660160af9edf244fc0626009374b98c3..fc40873b65124fc98a2e06150b7c8043f05ed4ab
--- 1/strbuf.h
--- 2/strbuf.h
+++ b/strbuf.h
@@@ -183,13 -183,16 +183,16 @@@ static inline void strbuf_setlen(struc
   * Strip whitespace from the beginning (`ltrim`), end (`rtrim`), or both side
   * (`trim`) of a string.
   */
 -extern void strbuf_trim(struct strbuf *);
 -extern void strbuf_rtrim(struct strbuf *);
 -extern void strbuf_ltrim(struct strbuf *);
 +void strbuf_trim(struct strbuf *sb);
 +void strbuf_rtrim(struct strbuf *sb);
 +void strbuf_ltrim(struct strbuf *sb);
  
  /* Strip trailing directory separators */
 -extern void strbuf_trim_trailing_dir_sep(struct strbuf *);
 +void strbuf_trim_trailing_dir_sep(struct strbuf *sb);
  
 -extern void strbuf_trim_trailing_newline(struct strbuf *sb);
+ /* Strip trailing LF or CR/LF */
++void strbuf_trim_trailing_newline(struct strbuf *sb);
+ 
  /**
   * Replace the contents of the strbuf with a reencoded form.  Returns -1
   * on error, 0 on success.