QtWebKit should not require SQLite version to 3.6.16.

Revert r152134 which raised the minimum SQLite version,
and r152201 which removed a method the reverted code needed.

Change-Id: Ie028992137f3983d114f3491423afe6303173544
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>

3 files changed, 32 insertions, 24 deletions

diff --git a/Source/WebCore/platform/sql/SQLiteFileSystem.cpp b/Source/WebCore/platform/sql/SQLiteFileSystem.cpp
index 735f0b41f..cbf8883ed 100644
--- a/Source/WebCore/platform/sql/SQLiteFileSystem.cpp
+++ b/Source/WebCore/platform/sql/SQLiteFileSystem.cpp
@@ -44,9 +44,11 @@ SQLiteFileSystem::SQLiteFileSystem()
 {
 }
 
-int SQLiteFileSystem::openDatabase(const String& filename, sqlite3** database, bool)
+int SQLiteFileSystem::openDatabase(const String& fileName, sqlite3** database, bool)
 {
-    return sqlite3_open(filename.utf8().data(), database);
+    // SQLite expects a null terminator on its UTF-16 strings.
+    String path = fileName;
+    return sqlite3_open16(path.deprecatedCharactersWithNullTermination(), database);
 }
 
 String SQLiteFileSystem::getFileNameForNewDatabase(const String& dbDir, const String&,
diff --git a/Source/WebCore/platform/sql/SQLiteFileSystem.h b/Source/WebCore/platform/sql/SQLiteFileSystem.h
index 14085b929..9800f7e54 100644
--- a/Source/WebCore/platform/sql/SQLiteFileSystem.h
+++ b/Source/WebCore/platform/sql/SQLiteFileSystem.h
@@ -46,13 +46,13 @@ class SQLiteFileSystem {
 public:
     // Opens a database file.
     //
-    // filemame - The name of the database file.
+    // fileName - The name of the database file.
     // database - The SQLite structure that represents the database stored
     //            in the given file.
     // forWebSQLDatabase - True, if and only if we're opening a Web SQL Database file.
     //                     Used by Chromium to determine if the DB file needs to be opened
     //                     using a custom VFS.
-    static int openDatabase(const String& filename, sqlite3** database, bool forWebSQLDatabase);
+    static int openDatabase(const String& fileName, sqlite3** database, bool forWebSQLDatabase);
 
     // Returns the file name for a database.
     //
diff --git a/Source/WebCore/platform/sql/SQLiteStatement.cpp b/Source/WebCore/platform/sql/SQLiteStatement.cpp
index 1203e84ee..fd2af3286 100644
--- a/Source/WebCore/platform/sql/SQLiteStatement.cpp
+++ b/Source/WebCore/platform/sql/SQLiteStatement.cpp
@@ -32,14 +32,18 @@
 #include <wtf/Assertions.h>
 #include <wtf/text/StringImpl.h>
 
-// SQLite 3.6.16 makes sqlite3_prepare_v2 automatically retry preparing the statement
-// once if the database scheme has changed. We rely on this behavior.
-#if SQLITE_VERSION_NUMBER < 3006016
-#error SQLite version 3.6.16 or newer is required
-#endif
-
 namespace WebCore {
 
+#if SQLITE_VERSION_NUMBER < 3003009
+
+// FIXME: This overload helps us compile with older versions of SQLite 3, but things like quotas will not work.
+static inline int sqlite3_prepare16_v2(sqlite3* db, const void* zSql, int nBytes, sqlite3_stmt** ppStmt, const void** pzTail)
+{
+    return sqlite3_prepare16(db, zSql, nBytes, ppStmt, pzTail);
+}
+
+#endif
+
 SQLiteStatement::SQLiteStatement(SQLiteDatabase& db, const String& sql)
     : m_database(db)
     , m_query(sql)
@@ -63,23 +67,25 @@ int SQLiteStatement::prepare()
     if (m_database.isInterrupted())
         return SQLITE_INTERRUPT;
 
-    CString query = m_query.stripWhiteSpace().utf8();
-    
-    LOG(SQLDatabase, "SQL - prepare - %s", query.data());
-
-    // Pass the length of the string including the null character to sqlite3_prepare_v2;
-    // this lets SQLite avoid an extra string copy.
-    size_t lengthIncludingNullCharacter = query.length() + 1;
-
-    const char* tail;
-    int error = sqlite3_prepare_v2(m_database.sqlite3Handle(), query.data(), lengthIncludingNullCharacter, &m_statement, &tail);
+    const void* tail = 0;
+    LOG(SQLDatabase, "SQL - prepare - %s", m_query.ascii().data());
+    String strippedQuery = m_query.stripWhiteSpace();
+    const UChar* nullTermed = strippedQuery.deprecatedCharactersWithNullTermination();
+    int error = sqlite3_prepare16_v2(m_database.sqlite3Handle(), nullTermed, -1, &m_statement, &tail);
+
+    // Starting with version 3.6.16, sqlite has a patch (http://www.sqlite.org/src/ci/256ec3c6af)
+    // that should make sure sqlite3_prepare16_v2 doesn't return a SQLITE_SCHEMA error.
+    // If we're using an older sqlite version, try to emulate the patch.
+    if (error == SQLITE_SCHEMA) {
+      sqlite3_finalize(m_statement);
+      error = sqlite3_prepare16_v2(m_database.sqlite3Handle(), m_query.deprecatedCharactersWithNullTermination(), -1, &m_statement, &tail);
+    }
 
     if (error != SQLITE_OK)
-        LOG(SQLDatabase, "sqlite3_prepare16 failed (%i)\n%s\n%s", error, query.data(), sqlite3_errmsg(m_database.sqlite3Handle()));
-
-    if (tail && *tail)
+        LOG(SQLDatabase, "sqlite3_prepare16 failed (%i)\n%s\n%s", error, m_query.ascii().data(), sqlite3_errmsg(m_database.sqlite3Handle()));
+    const UChar* ch = static_cast<const UChar*>(tail);
+    if (ch && *ch)
         error = SQLITE_ERROR;
-
 #ifndef NDEBUG
     m_isPrepared = error == SQLITE_OK;
 #endif