Index: Doc/Extra/Provider/version.html
==================================================================
--- Doc/Extra/Provider/version.html
+++ Doc/Extra/Provider/version.html
@@ -43,11 +43,12 @@
     <div id="mainSection">
     <div id="mainBody">
     <h1 class="heading">Version History</h1>
     <p><b>1.0.99.0 - December XX, 2015 <font color="red">(release scheduled)</font></b></p>
     <ul>
-      <li>Updated to <a href="https://www.sqlite.org/draft/releaselog/3_9_0.html">SQLite 3.9.0</a>.</li>
+      <li>Updated to <a href="https://www.sqlite.org/releaselog/3_9_1.html">SQLite 3.9.1</a>.</li>
+      <li>Permit an existing registered function to be replaced. Fix for <a href="https://system.data.sqlite.org/index.html/info/2556655d1b">[2556655d1b]</a>.</li>
       <li>Make GetValue work for boolean columns with textual &quot;True&quot; and &quot;False&quot; values. Fix for <a href="https://system.data.sqlite.org/index.html/info/7714b60d61">[7714b60d61]</a>.</li>
       <li>Add Reset method to the SQLiteCommand class.</li>
       <li>Add FileName property to the SQLiteConnection class.</li>
       <li>Add experimental support for the native json1 extension.</li>
     </ul>

Index: SQLite.Interop/props/sqlite3.props
==================================================================
--- SQLite.Interop/props/sqlite3.props
+++ SQLite.Interop/props/sqlite3.props
@@ -7,12 +7,12 @@
  * Released to the public domain, use at your own risk!
  *
 -->
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
   <PropertyGroup Label="UserMacros">
-    <SQLITE_MANIFEST_VERSION>3.9.0.0</SQLITE_MANIFEST_VERSION>
-    <SQLITE_RC_VERSION>3,9,0,0</SQLITE_RC_VERSION>
+    <SQLITE_MANIFEST_VERSION>3.9.1.0</SQLITE_MANIFEST_VERSION>
+    <SQLITE_RC_VERSION>3,9,1,0</SQLITE_RC_VERSION>
     <SQLITE_COMMON_DEFINES>_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT4=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1;SQLITE_ENABLE_MEMORY_MANAGEMENT=1;SQLITE_ENABLE_API_ARMOR=1</SQLITE_COMMON_DEFINES>
     <SQLITE_EXTRA_DEFINES>SQLITE_PLACEHOLDER=1;SQLITE_HAS_CODEC=1</SQLITE_EXTRA_DEFINES>
     <SQLITE_WINCE_200X_DEFINES>SQLITE_OMIT_WAL=1</SQLITE_WINCE_200X_DEFINES>
     <SQLITE_WINCE_2013_DEFINES>HAVE_ERRNO_H=1;SQLITE_MSVC_LOCALTIME_API=1</SQLITE_WINCE_2013_DEFINES>
     <SQLITE_DEBUG_DEFINES>SQLITE_DEBUG=1;SQLITE_MEMDEBUG=1;SQLITE_ENABLE_EXPENSIVE_ASSERT=1</SQLITE_DEBUG_DEFINES>

Index: SQLite.Interop/props/sqlite3.vsprops
==================================================================
--- SQLite.Interop/props/sqlite3.vsprops
+++ SQLite.Interop/props/sqlite3.vsprops
@@ -12,16 +12,16 @@
 	Version="8.00"
 	Name="sqlite3"
 	>
 	<UserMacro
 		Name="SQLITE_MANIFEST_VERSION"
-		Value="3.9.0.0"
+		Value="3.9.1.0"
 		PerformEnvironmentSet="true"
 	/>
 	<UserMacro
 		Name="SQLITE_RC_VERSION"
-		Value="3,9,0,0"
+		Value="3,9,1,0"
 		PerformEnvironmentSet="true"
 	/>
 	<UserMacro
 		Name="SQLITE_COMMON_DEFINES"
 		Value="_CRT_SECURE_NO_DEPRECATE;_CRT_SECURE_NO_WARNINGS;_CRT_NONSTDC_NO_DEPRECATE;_CRT_NONSTDC_NO_WARNINGS;SQLITE_THREADSAFE=1;SQLITE_USE_URI=1;SQLITE_ENABLE_COLUMN_METADATA=1;SQLITE_ENABLE_STAT4=1;SQLITE_ENABLE_FTS3=1;SQLITE_ENABLE_LOAD_EXTENSION=1;SQLITE_ENABLE_RTREE=1;SQLITE_SOUNDEX=1;SQLITE_ENABLE_MEMORY_MANAGEMENT=1;SQLITE_ENABLE_API_ARMOR=1"

Index: SQLite.Interop/src/core/sqlite3.c
==================================================================
--- SQLite.Interop/src/core/sqlite3.c
+++ SQLite.Interop/src/core/sqlite3.c
@@ -1,8 +1,8 @@
 /******************************************************************************
 ** This file is an amalgamation of many separate C source files from SQLite
-** version 3.9.0.  By combining all the individual C code files into this 
+** version 3.9.1.  By combining all the individual C code files into this 
 ** single large file, the entire code can be compiled as a single translation
 ** unit.  This allows many compilers to do optimizations that would not be
 ** possible if the files were compiled separately.  Performance improvements
 ** of 5% or more are commonly seen when SQLite is compiled as a single
 ** translation unit.
@@ -323,13 +323,13 @@
 **
 ** See also: [sqlite3_libversion()],
 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
 ** [sqlite_version()] and [sqlite_source_id()].
 */
-#define SQLITE_VERSION        "3.9.0"
-#define SQLITE_VERSION_NUMBER 3009000
-#define SQLITE_SOURCE_ID      "2015-10-14 12:29:53 a721fc0d89495518fe5612e2e3bbc60befd2e90d"
+#define SQLITE_VERSION        "3.9.1"
+#define SQLITE_VERSION_NUMBER 3009001
+#define SQLITE_SOURCE_ID      "2015-10-16 17:31:12 767c1727fec4ce11b83f25b3f1bfcfe68a2c8b02"
 
 /*
 ** CAPI3REF: Run-Time Library Version Numbers
 ** KEYWORDS: sqlite3_version, sqlite3_sourceid
 **
@@ -8156,11 +8156,10 @@
 
 
 #ifndef _FTS5_H
 #define _FTS5_H
 
-/* #include "sqlite3.h" */
 
 #if 0
 extern "C" {
 #endif
 
@@ -163560,11 +163559,10 @@
 /* #include "sqlite3ext.h" */
 #endif
 SQLITE_EXTENSION_INIT1
 /* #include <assert.h> */
 /* #include <string.h> */
-#include <ctype.h>  /* amalgamator: keep */
 /* #include <stdlib.h> */
 /* #include <stdarg.h> */
 
 #define UNUSED_PARAM(X)  (void)(X)
 
@@ -163575,20 +163573,29 @@
 
 /*
 ** Versions of isspace(), isalnum() and isdigit() to which it is safe
 ** to pass signed char values.
 */
-#define safe_isdigit(x) isdigit((unsigned char)(x))
-#define safe_isalnum(x) isalnum((unsigned char)(x))
+#ifdef sqlite3Isdigit
+   /* Use the SQLite core versions if this routine is part of the
+   ** SQLite amalgamation */
+#  define safe_isdigit(x) sqlite3Isdigit(x)
+#  define safe_isalnum(x) sqlite3Isalnum(x)
+#else
+   /* Use the standard library for separate compilation */
+#include <ctype.h>  /* amalgamator: keep */
+#  define safe_isdigit(x) isdigit((unsigned char)(x))
+#  define safe_isalnum(x) isalnum((unsigned char)(x))
+#endif
 
 /*
 ** Growing our own isspace() routine this way is twice as fast as
 ** the library isspace() function, resulting in a 7% overall performance
 ** increase for the parser.  (Ubuntu14.10 gcc 4.8.4 x64 with -Os).
 */
 static const char jsonIsSpace[] = {
-  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 1, 1, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
@@ -164046,11 +164053,17 @@
       int_done:
       break;
       int_as_real: /* fall through to real */;
     }
     case JSON_REAL: {
-      double r = strtod(pNode->u.zJContent, 0);
+      double r;
+#ifdef SQLITE_AMALGAMATION
+      const char *z = pNode->u.zJContent;
+      sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);
+#else
+      r = strtod(pNode->u.zJContent, 0);
+#endif
       sqlite3_result_double(pCtx, r);
       break;
     }
     case JSON_STRING: {
 #if 0 /* Never happens because JNODE_RAW is only set by json_set(),
@@ -165554,10 +165567,11 @@
 #endif
   return rc;
 }
 
 
+#ifndef SQLITE_CORE
 #ifdef _WIN32
 __declspec(dllexport)
 #endif
 SQLITE_API int SQLITE_STDCALL sqlite3_json_init(
   sqlite3 *db, 
@@ -165566,10 +165580,11 @@
 ){
   SQLITE_EXTENSION_INIT2(pApi);
   (void)pzErrMsg;  /* Unused parameter */
   return sqlite3Json1Init(db);
 }
+#endif
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1) */
 
 /************** End of json1.c ***********************************************/
 /************** Begin file fts5.c ********************************************/
 
@@ -180565,11 +180580,11 @@
   sqlite3_context *pCtx,          /* Function call context */
   int nArg,                       /* Number of args */
   sqlite3_value **apVal           /* Function arguments */
 ){
   assert( nArg==0 );
-  sqlite3_result_text(pCtx, "fts5: 2015-10-14 12:29:53 a721fc0d89495518fe5612e2e3bbc60befd2e90d", -1, SQLITE_TRANSIENT);
+  sqlite3_result_text(pCtx, "fts5: 2015-10-16 17:31:12 767c1727fec4ce11b83f25b3f1bfcfe68a2c8b02", -1, SQLITE_TRANSIENT);
 }
 
 static int fts5Init(sqlite3 *db){
   static const sqlite3_module fts5Mod = {
     /* iVersion      */ 2,

Index: SQLite.Interop/src/core/sqlite3.h
==================================================================
--- SQLite.Interop/src/core/sqlite3.h
+++ SQLite.Interop/src/core/sqlite3.h
@@ -109,13 +109,13 @@
 **
 ** See also: [sqlite3_libversion()],
 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
 ** [sqlite_version()] and [sqlite_source_id()].
 */
-#define SQLITE_VERSION        "3.9.0"
-#define SQLITE_VERSION_NUMBER 3009000
-#define SQLITE_SOURCE_ID      "2015-10-14 12:29:53 a721fc0d89495518fe5612e2e3bbc60befd2e90d"
+#define SQLITE_VERSION        "3.9.1"
+#define SQLITE_VERSION_NUMBER 3009001
+#define SQLITE_SOURCE_ID      "2015-10-16 17:31:12 767c1727fec4ce11b83f25b3f1bfcfe68a2c8b02"
 
 /*
 ** CAPI3REF: Run-Time Library Version Numbers
 ** KEYWORDS: sqlite3_version, sqlite3_sourceid
 **
@@ -7942,11 +7942,10 @@
 
 
 #ifndef _FTS5_H
 #define _FTS5_H
 
-#include "sqlite3.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 

Index: SQLite.Interop/src/ext/fts5.c
==================================================================
--- SQLite.Interop/src/ext/fts5.c
+++ SQLite.Interop/src/ext/fts5.c
@@ -15064,11 +15064,11 @@
   sqlite3_context *pCtx,          /* Function call context */
   int nArg,                       /* Number of args */
   sqlite3_value **apVal           /* Function arguments */
 ){
   assert( nArg==0 );
-  sqlite3_result_text(pCtx, "fts5: 2015-10-14 12:29:53 a721fc0d89495518fe5612e2e3bbc60befd2e90d", -1, SQLITE_TRANSIENT);
+  sqlite3_result_text(pCtx, "fts5: 2015-10-16 17:31:12 767c1727fec4ce11b83f25b3f1bfcfe68a2c8b02", -1, SQLITE_TRANSIENT);
 }
 
 static int fts5Init(sqlite3 *db){
   static const sqlite3_module fts5Mod = {
     /* iVersion      */ 2,

Index: SQLite.Interop/src/ext/json1.c
==================================================================
--- SQLite.Interop/src/ext/json1.c
+++ SQLite.Interop/src/ext/json1.c
@@ -26,11 +26,10 @@
 #include "sqlite3ext.h"
 #endif
 SQLITE_EXTENSION_INIT1
 #include <assert.h>
 #include <string.h>
-#include <ctype.h>  /* amalgamator: keep */
 #include <stdlib.h>
 #include <stdarg.h>
 
 #define UNUSED_PARAM(X)  (void)(X)
 
@@ -41,20 +40,29 @@
 
 /*
 ** Versions of isspace(), isalnum() and isdigit() to which it is safe
 ** to pass signed char values.
 */
-#define safe_isdigit(x) isdigit((unsigned char)(x))
-#define safe_isalnum(x) isalnum((unsigned char)(x))
+#ifdef sqlite3Isdigit
+   /* Use the SQLite core versions if this routine is part of the
+   ** SQLite amalgamation */
+#  define safe_isdigit(x) sqlite3Isdigit(x)
+#  define safe_isalnum(x) sqlite3Isalnum(x)
+#else
+   /* Use the standard library for separate compilation */
+#include <ctype.h>  /* amalgamator: keep */
+#  define safe_isdigit(x) isdigit((unsigned char)(x))
+#  define safe_isalnum(x) isalnum((unsigned char)(x))
+#endif
 
 /*
 ** Growing our own isspace() routine this way is twice as fast as
 ** the library isspace() function, resulting in a 7% overall performance
 ** increase for the parser.  (Ubuntu14.10 gcc 4.8.4 x64 with -Os).
 */
 static const char jsonIsSpace[] = {
-  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 1, 1, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
   0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
@@ -512,11 +520,17 @@
       int_done:
       break;
       int_as_real: /* fall through to real */;
     }
     case JSON_REAL: {
-      double r = strtod(pNode->u.zJContent, 0);
+      double r;
+#ifdef SQLITE_AMALGAMATION
+      const char *z = pNode->u.zJContent;
+      sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);
+#else
+      r = strtod(pNode->u.zJContent, 0);
+#endif
       sqlite3_result_double(pCtx, r);
       break;
     }
     case JSON_STRING: {
 #if 0 /* Never happens because JNODE_RAW is only set by json_set(),
@@ -2020,10 +2034,11 @@
 #endif
   return rc;
 }
 
 
+#ifndef SQLITE_CORE
 #ifdef _WIN32
 __declspec(dllexport)
 #endif
 int sqlite3_json_init(
   sqlite3 *db, 
@@ -2032,6 +2047,7 @@
 ){
   SQLITE_EXTENSION_INIT2(pApi);
   (void)pzErrMsg;  /* Unused parameter */
   return sqlite3Json1Init(db);
 }
+#endif
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1) */

Index: readme.htm
==================================================================
--- readme.htm
+++ readme.htm
@@ -4,11 +4,11 @@
 <title></title>
 </head>
 <body>
 ADO.NET SQLite Data Provider<br />
 Version 1.0.99.0 - December XX, 2015 <font color="red">(release scheduled)</font><br />
-Using <a href="https://www.sqlite.org/draft/releaselog/3_9_0.html">SQLite 3.9.0</a><br />
+Using <a href="https://www.sqlite.org/releaselog/3_9_1.html">SQLite 3.9.1</a><br />
 Originally written by Robert Simpson<br />
 Released to the public domain, use at your own risk!<br />
 Official provider website:&nbsp;<a href="https://system.data.sqlite.org/">https://system.data.sqlite.org/</a><br />
 Legacy versions:&nbsp;<a href="http://sqlite.phxsoftware.com/">http://sqlite.phxsoftware.com/</a><br />
 <br />
@@ -210,11 +210,12 @@
 
 <p>
     <b>1.0.99.0 - December XX, 2015 <font color="red">(release scheduled)</font></b>
 </p>
 <ul>
-    <li>Updated to <a href="https://www.sqlite.org/draft/releaselog/3_9_0.html">SQLite 3.9.0</a>.</li>
+    <li>Updated to <a href="https://www.sqlite.org/releaselog/3_9_1.html">SQLite 3.9.1</a>.</li>
+    <li>Permit an existing registered function to be replaced. Fix for [2556655d1b].</li>
     <li>Make GetValue work for boolean columns with textual &quot;True&quot; and &quot;False&quot; values. Fix for [7714b60d61].</li>
     <li>Add Reset method to the SQLiteCommand class.</li>
     <li>Add FileName property to the SQLiteConnection class.</li>
     <li>Add experimental support for the native json1 extension.</li>
 </ul>

Index: www/news.wiki
==================================================================
--- www/news.wiki
+++ www/news.wiki
@@ -4,11 +4,12 @@
 
 <p>
     <b>1.0.99.0 - December XX, 2015 <font color="red">(release scheduled)</font></b>
 </p>
 <ul>
-    <li>Updated to [https://www.sqlite.org/draft/releaselog/3_9_0.html|SQLite 3.9.0].</li>
+    <li>Updated to [https://www.sqlite.org/releaselog/3_9_1.html|SQLite 3.9.1].</li>
+    <li>Permit an existing registered function to be replaced. Fix for [2556655d1b].</li>
     <li>Make GetValue work for boolean columns with textual &quot;True&quot; and &quot;False&quot; values. Fix for [7714b60d61].</li>
     <li>Add Reset method to the SQLiteCommand class.</li>
     <li>Add FileName property to the SQLiteConnection class.</li>
     <li>Add experimental support for the native json1 extension.</li>
 </ul>