Fix Unary Negate Operation on Blobs

core/translate/expr.rs

@@ -1964,7 +1964,7 @@ pub fn translate_expr(
                 Ok(target_register)
             }
             (UnaryOperator::Negative, _) => {
-                let value = -1;
+                let value = 0;
 
                 let reg = program.alloc_register();
                 translate_expr(program, referenced_tables, expr, reg, resolver)?;
@@ -1974,7 +1974,7 @@ pub fn translate_expr(
                     dest: zero_reg,
                 });
                 program.mark_last_insn_constant();
-                program.emit_insn(Insn::Multiply {
+                program.emit_insn(Insn::Subtract {
                     lhs: zero_reg,
                     rhs: reg,
                     dest: target_register,

core/vdbe/execute.rs

@@ -5379,7 +5379,14 @@ pub fn exec_subtract(lhs: &OwnedValue, rhs: &OwnedValue) -> OwnedValue {
         (other, OwnedValue::Text(text)) => {
             exec_subtract(other, &cast_text_to_numeric(text.as_str()))
         }
-        _ => todo!(),
+        (other, OwnedValue::Blob(blob)) => {
+            let text = String::from_utf8_lossy(&blob);
+            exec_subtract(other, &cast_text_to_numeric(&text))
+        }
+        (OwnedValue::Blob(blob), other) => {
+            let text = String::from_utf8_lossy(&blob);
+            exec_subtract(&cast_text_to_numeric(&text), other)
+        }
     };
     match result {
         OwnedValue::Float(f) if f.is_nan() => OwnedValue::Null,

testing/math.test

@@ -95,6 +95,18 @@ do_execsql_test subtract-agg-float-agg-int {
   SELECT sum(3.5) - sum(1)
 } {2.5}
 
+do_execsql_test subtract-blob {
+  SELECT -x'11'
+} {0}
+
+do_execsql_test subtract-blob-empty {
+  SELECT -x''
+} {0}
+
+do_execsql_test subtract-blob-charcter {
+  SELECT -'hi';
+} {0}
+
 foreach {testnum lhs rhs ans} {
    1   'a'   'a'   0
    2   'a'   10    -10