# HG changeset patch
# User Christian Brabandt <cb@256bit.org>
# Date 1491669903 -7200
# Node ID ff27a6a3a243144efa913738cd19bb39b1603ace
# Parent  27e189283e9099f536c3614cc357e991629951bb
patch 8.0.0551: the typeahead buffer is reallocated too often

commit https://github.com/vim/vim/commit/d34f9b1155a6b470e1dc766ff98192f440e7eba7
Author: Bram Moolenaar <Bram@vim.org>
Date:   Sat Apr 8 18:41:13 2017 +0200

    patch 8.0.0551: the typeahead buffer is reallocated too often

    Problem:    The typeahead buffer is reallocated too often.
    Solution:   Re-use the existing buffer if possible.

diff --git a/src/getchar.c b/src/getchar.c
--- a/src/getchar.c
+++ b/src/getchar.c
@@ -920,7 +920,7 @@ init_typebuf(void)
 	typebuf.tb_noremap = noremapbuf_init;
 	typebuf.tb_buflen = TYPELEN_INIT;
 	typebuf.tb_len = 0;
-	typebuf.tb_off = 0;
+	typebuf.tb_off = MAXMAPLEN + 4;
 	typebuf.tb_change_cnt = 1;
     }
 }
@@ -974,11 +974,21 @@ ins_typebuf(
 	typebuf.tb_off -= addlen;
 	mch_memmove(typebuf.tb_buf + typebuf.tb_off, str, (size_t)addlen);
     }
+    else if (typebuf.tb_len == 0 && typebuf.tb_buflen
+					       >= addlen + 3 * (MAXMAPLEN + 4))
+    {
+	/*
+	 * Buffer is empty and string fits in the existing buffer.
+	 * Leave some space before and after, if possible.
+	 */
+	typebuf.tb_off = (typebuf.tb_buflen - addlen - 3 * (MAXMAPLEN + 4)) / 2;
+	mch_memmove(typebuf.tb_buf + typebuf.tb_off, str, (size_t)addlen);
+    }
     else
     {
 	/*
 	 * Need to allocate a new buffer.
-	 * In typebuf.tb_buf there must always be room for 3 * MAXMAPLEN + 4
+	 * In typebuf.tb_buf there must always be room for 3 * (MAXMAPLEN + 4)
 	 * characters.  We add some extra room to avoid having to allocate too
 	 * often.
 	 */
@@ -1291,7 +1301,7 @@ alloc_typebuf(void)
 	return FAIL;
     }
     typebuf.tb_buflen = TYPELEN_INIT;
-    typebuf.tb_off = 0;
+    typebuf.tb_off = MAXMAPLEN + 4;  /* can insert without realloc */
     typebuf.tb_len = 0;
     typebuf.tb_maplen = 0;
     typebuf.tb_silent = 0;
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    551,
+/**/
     550,
 /**/
     549,