From 78c0eafb3535fd70d74b9753b4e52f7a6225b5a2 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Thu, 15 Dec 2011 13:29:12 +0000
Subject: [PATCH] Make sure the chunksize in test_multiplex does not cause the
 pending byte to fall near the end of a chunk.  Adjust the chunksize upward as
 necessary to prevent this.

FossilOrigin-Name: e05f8a2998f4f4cbdb65702baa65893c538b3d38
---
 manifest             | 14 +++++++-------
 manifest.uuid        |  2 +-
 src/test_multiplex.c | 10 ++++++++++
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 33561aa1a4..21cbee27f3 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\ssome\sproblems\swith\sdropped\serror\scodes\sin\smultiplexOpen().
-D 2011-12-15T11:45:19.350
+C Make\ssure\sthe\schunksize\sin\stest_multiplex\sdoes\snot\scause\sthe\spending\sbyte\nto\sfall\snear\sthe\send\sof\sa\schunk.\s\sAdjust\sthe\schunksize\supward\sas\snecessary\nto\sprevent\sthis.
+D 2011-12-15T13:29:12.575
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5b4a3e12a850b021547e43daf886b25133b44c07
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -214,7 +214,7 @@ F src/test_intarray.h 489edb9068bb926583445cb02589344961054207
 F src/test_journal.c 03313c693cca72959dcaaf79f8d76f21c01e19ff
 F src/test_loadext.c df586c27176e3c2cb2e099c78da67bf14379a56e
 F src/test_malloc.c 8d416f29ad8573f32601f6056c9d2b17472e9ad5
-F src/test_multiplex.c 7e8d8303b8ba74ff50fbb40502522e576760266e
+F src/test_multiplex.c 7b65eea8b390dd223bd6e0ba9d7879389bd075c0
 F src/test_multiplex.h e99c571bc4968b7a9363b661481f3934bfead61d
 F src/test_mutex.c a6bd7b9cf6e19d989e31392b06ac8d189f0d573e
 F src/test_onefile.c 40cf9e212a377a6511469384a64b01e6e34b2eec
@@ -978,7 +978,7 @@ F tool/tostr.awk e75472c2f98dd76e06b8c9c1367f4ab07e122d06
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings-clang.sh 9f406d66e750e8ac031c63a9ef3248aaa347ef2a
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
-P a822a80d3cfe42b2fca6f8c9ff11762993114a27
-R 4637baef8720406f37351464996699d4
-U dan
-Z a1536baba57190ddd9d59e1c01fe9761
+P 2d50f78188e3297e8cefdf73cff51fa0a3b36e65
+R db6d46332c6333123f8fa60ccb204a1d
+U drh
+Z f65d5d73aa828ce8ac2cca0eb8289aa5
diff --git a/manifest.uuid b/manifest.uuid
index b07b3ebcac..ce1d054b8f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-2d50f78188e3297e8cefdf73cff51fa0a3b36e65
\ No newline at end of file
+e05f8a2998f4f4cbdb65702baa65893c538b3d38
\ No newline at end of file
diff --git a/src/test_multiplex.c b/src/test_multiplex.c
index f0d495f491..12e420fb5d 100644
--- a/src/test_multiplex.c
+++ b/src/test_multiplex.c
@@ -462,6 +462,16 @@ static int multiplexOpen(
       memcpy(pGroup->zName, zName, nName+1);
       pGroup->nName = nName;
     }
+    if( pGroup->bEnabled ){
+      /* Make sure that the chunksize is not such that the pending byte
+      ** falls at the end of a chunk.  A region of up to 64K following
+      ** the pending byte is never written, so if the pending byte occurs
+      ** near the end of a chunk, that chunk will be too small. */
+      extern int sqlite3PendingByte;
+      while( (sqlite3PendingByte % pGroup->szChunk)>=(pGroup->szChunk-65536) ){
+        pGroup->szChunk += 65536;
+      }
+    }
     pGroup->flags = flags;
     rc = multiplexSubFilename(pGroup, 1);
     if( rc==SQLITE_OK ){
-- 
2.47.2