Merge branch 'rs/strbuf-remove-fix' into maint

Code cleanup.

* rs/strbuf-remove-fix:
strbuf: use valid pointer in strbuf_remove()

diff --combined strbuf.c
index f3bd5719c636d10780e466e39f1145375c4cab68,e554f1f38c2a49d5a2d7bc42cb9b65745276f08d..b839be491b74a034cf848d2dd043aba7d75b7b92
--- 1/strbuf.c
--- 2/strbuf.c
+++ b/strbuf.c
@@@ -187,7 -187,7 +187,7 @@@ void strbuf_insert(struct strbuf *sb, s
  
  void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
  {
-       strbuf_splice(sb, pos, len, NULL, 0);
+       strbuf_splice(sb, pos, len, "", 0);
  }
  
  void strbuf_add(struct strbuf *sb, const void *data, size_t len)
@@@ -197,13 -197,6 +197,13 @@@
        strbuf_setlen(sb, sb->len + len);
  }
  
 +void strbuf_addbuf(struct strbuf *sb, const struct strbuf *sb2)
 +{
 +      strbuf_grow(sb, sb2->len);
 +      memcpy(sb->buf + sb->len, sb2->buf, sb2->len);
 +      strbuf_setlen(sb, sb->len + sb2->len);
 +}
 +
  void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len)
  {
        strbuf_grow(sb, len);
@@@ -402,12 -395,6 +402,12 @@@ ssize_t strbuf_read_once(struct strbuf 
        return cnt;
  }
  
 +ssize_t strbuf_write(struct strbuf *sb, FILE *f)
 +{
 +      return sb->len ? fwrite(sb->buf, 1, sb->len, f) : 0;
 +}
 +
 +
  #define STRBUF_MAXLINK (2*PATH_MAX)
  
  int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)