Check SQL query passed to execute

When `extra_check` feature is activated:
Fail when query has a column count > 0
Or when query is readonly.

.travis.yml

@@ -28,7 +28,7 @@ script:
   - cargo build --features sqlcipher
   - cargo build --features "bundled sqlcipher"
   - cargo test
-  - cargo test --features "backup blob"
+  - cargo test --features "backup blob extra_check"
   - cargo test --features "collation functions"
   - cargo test --features "hooks limits"
   - cargo test --features load_extension

Cargo.toml

@@ -48,12 +48,13 @@ csvtab = ["csv", "vtab"]
 # pointer passing interfaces: 3.20.0
 array = ["vtab"]
 # session extension: 3.13.0
-session = ["libsqlite3-sys/session", "hooks"]
+#session = ["libsqlite3-sys/session", "hooks"]
 # window functions: 3.25.0
 window = ["functions"]
 # 3.9.0
 series = ["vtab"]
-
+# check for invalid query.
+extra_check = []
 
 [dependencies]
 time = "0.1.0"

src/collation.rs

@@ -125,7 +125,9 @@ impl InnerConnection {
                     str::from_utf8_unchecked(c_slice)
                 };
                 callback(&conn, collation_name)
-            }).is_err() {
+            })
+            .is_err()
+            {
                 return; // FIXME How ?
             }
         }

src/lib.rs

@@ -890,7 +890,8 @@ mod test {
             )
             .expect("create temp db");
 
-        let mut db1 = Connection::open_with_flags(&path, OpenFlags::SQLITE_OPEN_READ_WRITE).unwrap();
+        let mut db1 =
+            Connection::open_with_flags(&path, OpenFlags::SQLITE_OPEN_READ_WRITE).unwrap();
         let mut db2 = Connection::open_with_flags(&path, OpenFlags::SQLITE_OPEN_READ_ONLY).unwrap();
 
         db1.busy_timeout(Duration::from_millis(0)).unwrap();

src/statement.rs

@@ -511,6 +511,7 @@ impl Statement<'_> {
     }
 
     fn execute_with_bound_parameters(&mut self) -> Result<usize> {
+        self.check_update()?;
         let r = self.stmt.step();
         self.stmt.reset();
         match r {
@@ -547,6 +548,30 @@ impl Statement<'_> {
         Ok(())
     }
 
+    #[cfg(all(feature = "bundled", feature = "extra_check"))]
+    #[inline]
+    fn check_update(&self) -> Result<()> {
+        if self.column_count() > 0 || self.stmt.readonly() {
+            return Err(Error::ExecuteReturnedResults);
+        }
+        Ok(())
+    }
+
+    #[cfg(all(not(feature = "bundled"), feature = "extra_check"))]
+    #[inline]
+    fn check_update(&self) -> Result<()> {
+        if self.column_count() > 0 {
+            return Err(Error::ExecuteReturnedResults);
+        }
+        Ok(())
+    }
+
+    #[cfg(not(feature = "extra_check"))]
+    #[inline]
+    fn check_update(&self) -> Result<()> {
+        Ok(())
+    }
+
     /// Returns a string containing the SQL text of prepared statement with
     /// bound parameters expanded.
     #[cfg(feature = "bundled")]