Update bundled sqlite to 3.25.2

[ChangeLog][Third-Party Code] Sqlite was updated to version 3.25.2

Change-Id: I2d74ee924745a5e1edd6fe511777965313a4b77a
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

1 files changed, 217 insertions, 78 deletions

diff --git a/src/3rdparty/sqlite/sqlite3.h b/src/3rdparty/sqlite/sqlite3.h
index 4427d2fa27..4612ecda7f 100644
--- a/src/3rdparty/sqlite/sqlite3.h
+++ b/src/3rdparty/sqlite/sqlite3.h
@@ -123,9 +123,9 @@ extern "C" {
 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
 ** [sqlite_version()] and [sqlite_source_id()].
 */
-#define SQLITE_VERSION        "3.24.0"
-#define SQLITE_VERSION_NUMBER 3024000
-#define SQLITE_SOURCE_ID      "2018-06-04 19:24:41 c7ee0833225bfd8c5ec2f9bf62b97c4e04d03bd9566366d5221ac8fb199a87ca"
+#define SQLITE_VERSION        "3.25.2"
+#define SQLITE_VERSION_NUMBER 3025002
+#define SQLITE_SOURCE_ID      "2018-09-25 19:08:10 fb90e7189ae6d62e77ba3a308ca5d683f90bbe633cf681865365b8e92792d1c7"
 
 /*
 ** CAPI3REF: Run-Time Library Version Numbers
@@ -472,6 +472,7 @@ SQLITE_API int sqlite3_exec(
 */
 #define SQLITE_ERROR_MISSING_COLLSEQ   (SQLITE_ERROR | (1<<8))
 #define SQLITE_ERROR_RETRY             (SQLITE_ERROR | (2<<8))
+#define SQLITE_ERROR_SNAPSHOT          (SQLITE_ERROR | (3<<8))
 #define SQLITE_IOERR_READ              (SQLITE_IOERR | (1<<8))
 #define SQLITE_IOERR_SHORT_READ        (SQLITE_IOERR | (2<<8))
 #define SQLITE_IOERR_WRITE             (SQLITE_IOERR | (3<<8))
@@ -511,6 +512,7 @@ SQLITE_API int sqlite3_exec(
 #define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
 #define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
 #define SQLITE_CANTOPEN_CONVPATH       (SQLITE_CANTOPEN | (4<<8))
+#define SQLITE_CANTOPEN_DIRTYWAL       (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
 #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
 #define SQLITE_CORRUPT_SEQUENCE        (SQLITE_CORRUPT | (2<<8))
 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
@@ -886,7 +888,8 @@ struct sqlite3_io_methods {
 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
 ** persistent [WAL | Write Ahead Log] setting.  By default, the auxiliary
-** write ahead log and shared memory files used for transaction control
+** write ahead log ([WAL file]) and shared memory
+** files used for transaction control
 ** are automatically deleted when the latest connection to the database
 ** closes.  Setting persistent WAL mode causes those files to persist after
 ** close.  Persisting the files is useful when other processes that do not
@@ -1072,6 +1075,26 @@ struct sqlite3_io_methods {
 ** a file lock using the xLock or xShmLock methods of the VFS to wait
 ** for up to M milliseconds before failing, where M is the single 
 ** unsigned integer parameter.
+**
+** <li>[[SQLITE_FCNTL_DATA_VERSION]]
+** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
+** a database file.  The argument is a pointer to a 32-bit unsigned integer.
+** The "data version" for the pager is written into the pointer.  The
+** "data version" changes whenever any change occurs to the corresponding
+** database file, either through SQL statements on the same database
+** connection or through transactions committed by separate database
+** connections possibly in other processes. The [sqlite3_total_changes()]
+** interface can be used to find if any database on the connection has changed,
+** but that interface responds to changes on TEMP as well as MAIN and does
+** not provide a mechanism to detect changes to MAIN only.  Also, the
+** [sqlite3_total_changes()] interface responds to internal changes only and
+** omits changes made by other database connections.  The
+** [PRAGMA data_version] command provide a mechanism to detect changes to
+** a single attached database that occur due to other database connections,
+** but omits changes implemented by the database connection on which it is
+** called.  This file control is the only mechanism to detect changes that
+** happen either internally or externally and that are associated with
+** a particular attached database.
 ** </ul>
 */
 #define SQLITE_FCNTL_LOCKSTATE               1
@@ -1107,6 +1130,7 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE    32
 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE  33
 #define SQLITE_FCNTL_LOCK_TIMEOUT           34
+#define SQLITE_FCNTL_DATA_VERSION           35
 
 /* deprecated names */
 #define SQLITE_GET_LOCKPROXYFILE      SQLITE_FCNTL_GET_LOCKPROXYFILE
@@ -2121,6 +2145,12 @@ struct sqlite3_mem_methods {
 ** with no schema and no content. The following process works even for
 ** a badly corrupted database file:
 ** <ol>
+** <li> If the database connection is newly opened, make sure it has read the
+**      database schema by preparing then discarding some query against the
+**      database, or calling sqlite3_table_column_metadata(), ignoring any
+**      errors.  This step is only necessary if the application desires to keep
+**      the database in WAL mode after the reset if it was in WAL mode before
+**      the reset.  
 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
@@ -2269,12 +2299,17 @@ SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
 ** program, the value returned reflects the number of rows modified by the 
 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
 **
-** See also the [sqlite3_total_changes()] interface, the
-** [count_changes pragma], and the [changes() SQL function].
-**
 ** If a separate thread makes changes on the same database connection
 ** while [sqlite3_changes()] is running then the value returned
 ** is unpredictable and not meaningful.
+**
+** See also:
+** <ul>
+** <li> the [sqlite3_total_changes()] interface
+** <li> the [count_changes pragma]
+** <li> the [changes() SQL function]
+** <li> the [data_version pragma]
+** </ul>
 */
 SQLITE_API int sqlite3_changes(sqlite3*);
 
@@ -2292,13 +2327,26 @@ SQLITE_API int sqlite3_changes(sqlite3*);
 ** count, but those made as part of REPLACE constraint resolution are
 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 
 ** are not counted.
-** 
-** See also the [sqlite3_changes()] interface, the
-** [count_changes pragma], and the [total_changes() SQL function].
 **
+** This the [sqlite3_total_changes(D)] interface only reports the number
+** of rows that changed due to SQL statement run against database
+** connection D.  Any changes by other database connections are ignored.
+** To detect changes against a database file from other database
+** connections use the [PRAGMA data_version] command or the
+** [SQLITE_FCNTL_DATA_VERSION] [file control].
+** 
 ** If a separate thread makes changes on the same database connection
 ** while [sqlite3_total_changes()] is running then the value
 ** returned is unpredictable and not meaningful.
+**
+** See also:
+** <ul>
+** <li> the [sqlite3_changes()] interface
+** <li> the [count_changes pragma]
+** <li> the [changes() SQL function]
+** <li> the [data_version pragma]
+** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
+** </ul>
 */
 SQLITE_API int sqlite3_total_changes(sqlite3*);
 
@@ -3354,13 +3402,24 @@ SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int
 ** [database connection] D failed, then the sqlite3_errcode(D) interface
 ** returns the numeric [result code] or [extended result code] for that
 ** API call.
-** If the most recent API call was successful,
-** then the return value from sqlite3_errcode() is undefined.
 ** ^The sqlite3_extended_errcode()
 ** interface is the same except that it always returns the 
 ** [extended result code] even when extended result codes are
 ** disabled.
 **
+** The values returned by sqlite3_errcode() and/or
+** sqlite3_extended_errcode() might change with each API call.
+** Except, there are some interfaces that are guaranteed to never
+** change the value of the error code.  The error-code preserving
+** interfaces are:
+**
+** <ul>
+** <li> sqlite3_errcode()
+** <li> sqlite3_extended_errcode()
+** <li> sqlite3_errmsg()
+** <li> sqlite3_errmsg16()
+** </ul>
+**
 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
 ** text that describes the error, as either UTF-8 or UTF-16 respectively.
 ** ^(Memory to hold the error message string is managed internally.
@@ -4514,11 +4573,25 @@ SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
 ** [sqlite3_free()].
 **
-** ^(If a memory allocation error occurs during the evaluation of any
-** of these routines, a default value is returned.  The default value
-** is either the integer 0, the floating point number 0.0, or a NULL
-** pointer.  Subsequent calls to [sqlite3_errcode()] will return
-** [SQLITE_NOMEM].)^
+** As long as the input parameters are correct, these routines will only
+** fail if an out-of-memory error occurs during a format conversion.
+** Only the following subset of interfaces are subject to out-of-memory
+** errors:
+**
+** <ul>
+** <li> sqlite3_column_blob()
+** <li> sqlite3_column_text()
+** <li> sqlite3_column_text16()
+** <li> sqlite3_column_bytes()
+** <li> sqlite3_column_bytes16()
+** </ul>
+**
+** If an out-of-memory error occurs, then the return value from these
+** routines is the same as if the column had contained an SQL NULL value.
+** Valid SQL NULL returns can be distinguished from out-of-memory errors
+** by invoking the [sqlite3_errcode()] immediately after the suspect
+** return value is obtained and before any
+** other SQLite interface is called on the same [database connection].
 */
 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
@@ -4595,11 +4668,13 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
 **
 ** ^These functions (collectively known as "function creation routines")
 ** are used to add SQL functions or aggregates or to redefine the behavior
-** of existing SQL functions or aggregates.  The only differences between
-** these routines are the text encoding expected for
-** the second parameter (the name of the function being created)
-** and the presence or absence of a destructor callback for
-** the application data pointer.
+** of existing SQL functions or aggregates. The only differences between
+** the three "sqlite3_create_function*" routines are the text encoding 
+** expected for the second parameter (the name of the function being 
+** created) and the presence or absence of a destructor callback for
+** the application data pointer. Function sqlite3_create_window_function()
+** is similar, but allows the user to supply the extra callback functions
+** needed by [aggregate window functions].
 **
 ** ^The first parameter is the [database connection] to which the SQL
 ** function is to be added.  ^If an application uses more than one database
@@ -4645,7 +4720,8 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
 ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
 ** function can gain access to this pointer using [sqlite3_user_data()].)^
 **
-** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
+** ^The sixth, seventh and eighth parameters passed to the three
+** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
 ** pointers to C-language functions that implement the SQL function or
 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
 ** callback only; NULL pointers must be passed as the xStep and xFinal
@@ -4654,15 +4730,24 @@ SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
 ** SQL function or aggregate, pass NULL pointers for all three function
 ** callbacks.
 **
-** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
-** then it is destructor for the application data pointer. 
-** The destructor is invoked when the function is deleted, either by being
-** overloaded or when the database connection closes.)^
-** ^The destructor is also invoked if the call to
-** sqlite3_create_function_v2() fails.
-** ^When the destructor callback of the tenth parameter is invoked, it
-** is passed a single argument which is a copy of the application data 
-** pointer which was the fifth parameter to sqlite3_create_function_v2().
+** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 
+** and xInverse) passed to sqlite3_create_window_function are pointers to
+** C-language callbacks that implement the new function. xStep and xFinal
+** must both be non-NULL. xValue and xInverse may either both be NULL, in
+** which case a regular aggregate function is created, or must both be 
+** non-NULL, in which case the new function may be used as either an aggregate
+** or aggregate window function. More details regarding the implementation
+** of aggregate window functions are 
+** [user-defined window functions|available here].
+**
+** ^(If the final parameter to sqlite3_create_function_v2() or
+** sqlite3_create_window_function() is not NULL, then it is destructor for
+** the application data pointer. The destructor is invoked when the function 
+** is deleted, either by being overloaded or when the database connection 
+** closes.)^ ^The destructor is also invoked if the call to 
+** sqlite3_create_function_v2() fails.  ^When the destructor callback is
+** invoked, it is passed a single argument which is a copy of the application
+** data pointer which was the fifth parameter to sqlite3_create_function_v2().
 **
 ** ^It is permitted to register multiple implementations of the same
 ** functions with the same name but with either differing numbers of
@@ -4715,6 +4800,18 @@ SQLITE_API int sqlite3_create_function_v2(
   void (*xFinal)(sqlite3_context*),
   void(*xDestroy)(void*)
 );
+SQLITE_API int sqlite3_create_window_function(
+  sqlite3 *db,
+  const char *zFunctionName,
+  int nArg,
+  int eTextRep,
+  void *pApp,
+  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
+  void (*xFinal)(sqlite3_context*),
+  void (*xValue)(sqlite3_context*),
+  void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
+  void(*xDestroy)(void*)
+);
 
 /*
 ** CAPI3REF: Text Encodings
@@ -4857,6 +4954,28 @@ SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int6
 **
 ** These routines must be called from the same thread as
 ** the SQL function that supplied the [sqlite3_value*] parameters.
+**
+** As long as the input parameter is correct, these routines can only
+** fail if an out-of-memory error occurs during a format conversion.
+** Only the following subset of interfaces are subject to out-of-memory
+** errors:
+**
+** <ul>
+** <li> sqlite3_value_blob()
+** <li> sqlite3_value_text()
+** <li> sqlite3_value_text16()
+** <li> sqlite3_value_text16le()
+** <li> sqlite3_value_text16be()
+** <li> sqlite3_value_bytes()
+** <li> sqlite3_value_bytes16()
+** </ul>
+**
+** If an out-of-memory error occurs, then the return value from these
+** routines is the same as if the column had contained an SQL NULL value.
+** Valid SQL NULL returns can be distinguished from out-of-memory errors
+** by invoking the [sqlite3_errcode()] immediately after the suspect
+** return value is obtained and before any
+** other SQLite interface is called on the same [database connection].
 */
 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
 SQLITE_API double sqlite3_value_double(sqlite3_value*);
@@ -6323,6 +6442,7 @@ struct sqlite3_index_info {
 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
 #define SQLITE_INDEX_CONSTRAINT_ISNULL    71
 #define SQLITE_INDEX_CONSTRAINT_IS        72
+#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
 
 /*
 ** CAPI3REF: Register A Virtual Table Implementation
@@ -6999,6 +7119,7 @@ SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
 /*
 ** CAPI3REF: Low-Level Control Of Database Files
 ** METHOD: sqlite3
+** KEYWORDS: {file control}
 **
 ** ^The [sqlite3_file_control()] interface makes a direct call to the
 ** xFileControl method for the [sqlite3_io_methods] object associated
@@ -7013,11 +7134,18 @@ SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
 ** the xFileControl method.  ^The return value of the xFileControl
 ** method becomes the return value of this routine.
 **
+** A few opcodes for [sqlite3_file_control()] are handled directly
+** by the SQLite core and never invoke the 
+** sqlite3_io_methods.xFileControl method.
 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
 ** a pointer to the underlying [sqlite3_file] object to be written into
-** the space pointed to by the 4th parameter.  ^The [SQLITE_FCNTL_FILE_POINTER]
-** case is a short-circuit path which does not actually invoke the
-** underlying sqlite3_io_methods.xFileControl method.
+** the space pointed to by the 4th parameter.  The
+** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
+** the [sqlite3_file] object associated with the journal file instead of
+** the main database.  The [SQLITE_FCNTL_VFS_POINTER] opcode returns
+** a pointer to the underlying [sqlite3_vfs] object for the file.
+** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
+** from the pager.
 **
 ** ^If the second parameter (zDbName) does not match the name of any
 ** open database file, then SQLITE_ERROR is returned.  ^This error
@@ -8836,7 +8964,6 @@ SQLITE_API int sqlite3_system_errno(sqlite3*);
 /*
 ** CAPI3REF: Database Snapshot
 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
-** EXPERIMENTAL
 **
 ** An instance of the snapshot object records the state of a [WAL mode]
 ** database for some specific point in history.
@@ -8853,11 +8980,6 @@ SQLITE_API int sqlite3_system_errno(sqlite3*);
 ** version of the database file so that it is possible to later open a new read
 ** transaction that sees that historical version of the database rather than
 ** the most recent version.
-**
-** The constructor for this object is [sqlite3_snapshot_get()].  The
-** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
-** to an historical snapshot (if possible).  The destructor for 
-** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
 */
 typedef struct sqlite3_snapshot {
   unsigned char hidden[48];
@@ -8865,7 +8987,7 @@ typedef struct sqlite3_snapshot {
 
 /*
 ** CAPI3REF: Record A Database Snapshot
-** EXPERIMENTAL
+** CONSTRUCTOR: sqlite3_snapshot
 **
 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
 ** new [sqlite3_snapshot] object that records the current state of
@@ -8881,7 +9003,7 @@ typedef struct sqlite3_snapshot {
 ** in this case. 
 **
 ** <ul>
-**   <li> The database handle must be in [autocommit mode].
+**   <li> The database handle must not be in [autocommit mode].
 **
 **   <li> Schema S of [database connection] D must be a [WAL mode] database.
 **
@@ -8904,7 +9026,7 @@ typedef struct sqlite3_snapshot {
 ** to avoid a memory leak.
 **
 ** The [sqlite3_snapshot_get()] interface is only available when the
-** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
 */
 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
   sqlite3 *db,
@@ -8914,24 +9036,35 @@ SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
 
 /*
 ** CAPI3REF: Start a read transaction on an historical snapshot
-** EXPERIMENTAL
+** METHOD: sqlite3_snapshot
+**
+** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 
+** transaction or upgrades an existing one for schema S of 
+** [database connection] D such that the read transaction refers to 
+** historical [snapshot] P, rather than the most recent change to the 
+** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 
+** on success or an appropriate [error code] if it fails.
+**
+** ^In order to succeed, the database connection must not be in 
+** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
+** is already a read transaction open on schema S, then the database handle
+** must have no active statements (SELECT statements that have been passed
+** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 
+** SQLITE_ERROR is returned if either of these conditions is violated, or
+** if schema S does not exist, or if the snapshot object is invalid.
+**
+** ^A call to sqlite3_snapshot_open() will fail to open if the specified
+** snapshot has been overwritten by a [checkpoint]. In this case 
+** SQLITE_ERROR_SNAPSHOT is returned.
+**
+** If there is already a read transaction open when this function is 
+** invoked, then the same read transaction remains open (on the same
+** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
+** is returned. If another error code - for example SQLITE_PROTOCOL or an
+** SQLITE_IOERR error code - is returned, then the final state of the
+** read transaction is undefined. If SQLITE_OK is returned, then the 
+** read transaction is now open on database snapshot P.
 **
-** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
-** read transaction for schema S of
-** [database connection] D such that the read transaction
-** refers to historical [snapshot] P, rather than the most
-** recent change to the database.
-** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
-** or an appropriate [error code] if it fails.
-**
-** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
-** the first operation following the [BEGIN] that takes the schema S
-** out of [autocommit mode].
-** ^In other words, schema S must not currently be in
-** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
-** database connection D must be out of [autocommit mode].
-** ^A [snapshot] will fail to open if it has been overwritten by a
-** [checkpoint].
 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
 ** database connection D does not know that the database file for
 ** schema S is in [WAL mode].  A database connection might not know
@@ -8942,7 +9075,7 @@ SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
 ** database connection in order to make it ready to use snapshots.)
 **
 ** The [sqlite3_snapshot_open()] interface is only available when the
-** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
 */
 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
   sqlite3 *db,
@@ -8952,20 +9085,20 @@ SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
 
 /*
 ** CAPI3REF: Destroy a snapshot
-** EXPERIMENTAL
+** DESTRUCTOR: sqlite3_snapshot
 **
 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
 ** The application must eventually free every [sqlite3_snapshot] object
 ** using this routine to avoid a memory leak.
 **
 ** The [sqlite3_snapshot_free()] interface is only available when the
-** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
+** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
 */
 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
 
 /*
 ** CAPI3REF: Compare the ages of two snapshot handles.
-** EXPERIMENTAL
+** METHOD: sqlite3_snapshot
 **
 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
 ** of two valid snapshot handles. 
@@ -8984,6 +9117,9 @@ SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
 ** Otherwise, this API returns a negative value if P1 refers to an older
 ** snapshot than P2, zero if the two handles refer to the same database
 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
+**
+** This interface is only available if SQLite is compiled with the
+** [SQLITE_ENABLE_SNAPSHOT] option.
 */
 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
   sqlite3_snapshot *p1,
@@ -8992,23 +9128,26 @@ SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
 
 /*
 ** CAPI3REF: Recover snapshots from a wal file
-** EXPERIMENTAL
+** METHOD: sqlite3_snapshot
 **
-** If all connections disconnect from a database file but do not perform
-** a checkpoint, the existing wal file is opened along with the database
-** file the next time the database is opened. At this point it is only
-** possible to successfully call sqlite3_snapshot_open() to open the most
-** recent snapshot of the database (the one at the head of the wal file),
-** even though the wal file may contain other valid snapshots for which
-** clients have sqlite3_snapshot handles.
+** If a [WAL file] remains on disk after all database connections close
+** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
+** or because the last process to have the database opened exited without
+** calling [sqlite3_close()]) and a new connection is subsequently opened
+** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
+** will only be able to open the last transaction added to the WAL file
+** even though the WAL file contains other valid transactions.
 **
-** This function attempts to scan the wal file associated with database zDb
+** This function attempts to scan the WAL file associated with database zDb
 ** of database handle db and make all valid snapshots available to
 ** sqlite3_snapshot_open(). It is an error if there is already a read
-** transaction open on the database, or if the database is not a wal mode
+** transaction open on the database, or if the database is not a WAL mode
 ** database.
 **
 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
+**
+** This interface is only available if SQLite is compiled with the
+** [SQLITE_ENABLE_SNAPSHOT] option.
 */
 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
 
@@ -9119,7 +9258,7 @@ SQLITE_API int sqlite3_deserialize(
 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
 ** and that SQLite should take ownership of this memory and automatically
 ** free it when it has finished using it.  Without this flag, the caller
-** is resposible for freeing any dynamically allocated memory.
+** is responsible for freeing any dynamically allocated memory.
 **
 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
 ** grow the size of the database using calls to [sqlite3_realloc64()].  This
@@ -11297,7 +11436,7 @@ struct Fts5ExtensionApi {
 **            This way, even if the tokenizer does not provide synonyms
 **            when tokenizing query text (it should not - to do would be
 **            inefficient), it doesn't matter if the user queries for 
-**            'first + place' or '1st + place', as there are entires in the
+**            'first + place' or '1st + place', as there are entries in the
 **            FTS index corresponding to both forms of the first token.
 **   </ol>
 **
@@ -11325,7 +11464,7 @@ struct Fts5ExtensionApi {
 **   extra data to the FTS index or require FTS5 to query for multiple terms,
 **   so it is efficient in terms of disk space and query speed. However, it
 **   does not support prefix queries very well. If, as suggested above, the
-**   token "first" is subsituted for "1st" by the tokenizer, then the query:
+**   token "first" is substituted for "1st" by the tokenizer, then the query:
 **
 **   <codeblock>
 **     ... MATCH '1s*'</codeblock>