Reduce allocations in QSQLiteDriver::open()'s connection options parsing

- Use splitRef() instead of split(), avoiding small temporary
  QStrings.
- Don't remove all spaces before splitting, trim strings at
  the QStringRef level later, where needed. This will reject
  nonsense strings like QSQL_ LITE _BUSY_ TI MEOUT= 1 2 3 that
  were previously (wrongly) accepted.
- Use C++11 range-for loop.

Change-Id: I875c4cf47b7a283ba55783f70c903bb9947e1cd7
Reviewed-by: Mark Brand <mabrand@mabrand.nl>

1 files changed, 11 insertions, 7 deletions

diff --git a/src/sql/drivers/sqlite/qsql_sqlite.cpp b/src/sql/drivers/sqlite/qsql_sqlite.cpp
index c1071c9222..1fff427a66 100644
--- a/src/sql/drivers/sqlite/qsql_sqlite.cpp
+++ b/src/sql/drivers/sqlite/qsql_sqlite.cpp
@@ -613,13 +613,17 @@ bool QSQLiteDriver::open(const QString & db, const QString &, const QString &, c
     bool openReadOnlyOption = false;
     bool openUriOption = false;
 
-    const QStringList opts = QString(conOpts).remove(QLatin1Char(' ')).split(QLatin1Char(';'));
-    foreach (const QString &option, opts) {
-        if (option.startsWith(QLatin1String("QSQLITE_BUSY_TIMEOUT="))) {
-            bool ok;
-            const int nt = option.midRef(21).toInt(&ok);
-            if (ok)
-                timeOut = nt;
+    const auto opts = conOpts.splitRef(QLatin1Char(';'));
+    for (auto option : opts) {
+        option = option.trimmed();
+        if (option.startsWith(QLatin1String("QSQLITE_BUSY_TIMEOUT"))) {
+            option = option.mid(20).trimmed();
+            if (option.startsWith(QLatin1Char('='))) {
+                bool ok;
+                const int nt = option.mid(1).trimmed().toInt(&ok);
+                if (ok)
+                    timeOut = nt;
+            }
         } else if (option == QLatin1String("QSQLITE_OPEN_READONLY")) {
             openReadOnlyOption = true;
         } else if (option == QLatin1String("QSQLITE_OPEN_URI")) {