[c++ options] Restore forward & backward compatibility, fix crash.

Store Number Range option values as a pair '(percentage . value) or '(pixels .
value) depending on the size of value as 4.x and earlier expect. When reading a
stored number range option handle the possibility that value is fixed
point (e.g. 50.0) as 4.x and earlier emit, avoiding a crash.

bindings/guile/gnc-optiondb.i

@@ -1080,6 +1080,18 @@ wrap_unique_ptr(GncOptionDBPtr, GncOptionDB);
         return scm_cons(desig, scm_from_int(val));
     }
 
+    static SCM
+    get_scm_value(const GncOptionRangeValue<double>& option)
+    {
+        return scm_from_double(option.get_value());
+    }
+
+    static SCM
+    get_scm_default_value(const GncOptionRangeValue<double>& option)
+    {
+        return scm_from_double(option.get_default_value());
+    }
+
     static SCM
     get_scm_value(const GncOptionDateValue& option)
     {
@@ -1285,14 +1297,14 @@ inline SCM return_scm_value(ValueType value)
                               is_same_decayed_v<decltype(option),
                               GncOptionRangeValue<double>>)
                 {
-                    auto serial{option.serialize()};
-                    if (serial.empty())
+                    auto serial{get_scm_value(option)};
+                    if (serial == SCM_BOOL_F)
                     {
                         return no_value;
                     }
                     else
                     {
-                        auto scm_str{scm_list_1(scm_from_utf8_string(serial.c_str()))};
+                        auto scm_str{scm_list_1(serial)};
                         return scm_simple_format(SCM_BOOL_F, ticked_format_str, scm_str);
                     }
                 }
@@ -1368,10 +1380,11 @@ inline SCM return_scm_value(ValueType value)
                     if constexpr (is_same_decayed_v<decltype(option),
                                   GncOptionRangeValue<int>>)
                     {
-                        if (scm_is_pair(new_value))
-                            option.set_value(scm_to_int(scm_cdr(new_value)));
-                        else
-                            option.set_value(scm_to_int(new_value));
+                        auto value_num{scm_is_pair(new_value) ? scm_cdr(new_value) : new_value};
+                        int value_int = scm_is_exact_integer(value_num) ?
+                            scm_to_int(value_num) :
+                            static_cast<int>(scm_to_double(value_num));
+                        option.set_value(value_int);
                         return;
                     }
                     if constexpr (is_same_decayed_v<decltype(option),

bindings/guile/test/test-gnc-option-scheme-output.scm

@@ -127,6 +127,21 @@
 "
           (gncBudgetGetGUID value)))
 
+(define (test-number-range-output-template value)
+  (format #f "
+; Section: foo
+
+(let ((option (gnc:lookup-option options
+                                 \"foo\"
+                                 \"bar\")))
+  ((lambda (o) (if o (gnc:option-set-value o ~a))) option))
+
+" (if (exact-integer? value)
+      (if (< value 100)
+          (format #f "'(percent . ~d)" value)
+          (format #f "'(pixels . ~f)" value))
+      (format #f "'~f" value)
+      )))
 
 (define (test-option-scheme-output name make-option-func get-value-func test-template default value)
   (let ((odb (gnc:new-options))
@@ -438,10 +453,10 @@ veritatis et quasi architecto beatae vitae dicta sunt, explicabo.")
       (test-equal "number-range unchanged" test-unchanged-section-output-template
                   (gnc:generate-restore-forms odb "options"))
       (let ((option (gnc:lookup-option odb "foo" "bar"))
-            (test-template test-literal-output-template))
+            (test-template test-number-range-output-template))
         (gnc:option-set-value option 42.0)
         (test-equal "number-range form"
-                    (test-template (GncOption-serialize option))
+                    (test-template (string->number (GncOption-serialize option)))
                     (gnc:generate-restore-forms odb "options"))
         ))
     (test-end  "test-gnc-number-range-option-to-scheme"))
@@ -460,10 +475,10 @@ veritatis et quasi architecto beatae vitae dicta sunt, explicabo.")
       (test-equal "number-plot unchanged" test-unchanged-section-output-template
                   (gnc:generate-restore-forms odb "options"))
       (let ((option (gnc:lookup-option odb "foo" "bar"))
-            (test-template test-literal-output-template))
-        (gnc:option-set-value option 42)
+            (test-template test-number-range-output-template))
+        (gnc:option-set-value option 48)
         (test-equal "number-plot form"
-                    (test-template (GncOption-serialize option))
+                    (test-template (string->number (GncOption-serialize option)))
                     (gnc:generate-restore-forms odb "options"))
         ))
     (test-end  "test-gnc-number-plot-size-option-to-scheme"))