tests: Add non-precise fractional scaling test

https://bugzilla.gnome.org/show_bug.cgi?id=765011

src/tests/monitor-configs/high-precision-fractional-scale.xml

@@ -0,0 +1,23 @@
+<monitors version="2">
+  <configuration>
+    <logicalmonitor>
+      <x>0</x>
+      <y>0</y>
+      <primary>yes</primary>
+      <scale>1.3763440847396851</scale>
+      <monitor>
+	<monitorspec>
+	  <connector>DP-1</connector>
+	  <vendor>MetaProduct's Inc.</vendor>
+	  <product>MetaMonitor</product>
+	  <serial>0x123456</serial>
+	</monitorspec>
+	<mode>
+	  <width>1024</width>
+	  <height>768</height>
+	  <rate>60.000495910644531</rate>
+	</mode>
+      </monitor>
+    </logicalmonitor>
+  </configuration>
+</monitors>

src/tests/monitor-store-unit-tests.c

@@ -577,6 +577,62 @@ meta_test_monitor_store_fractional_scale (void)
   check_monitor_configurations (&expect);
 }
 
+static void
+meta_test_monitor_store_high_precision_fractional_scale (void)
+{
+  MonitorStoreTestExpect expect = {
+    .configurations = {
+      {
+        .logical_monitors = {
+          {
+            .layout = {
+              .x = 0,
+              .y = 0,
+              .width = 744,
+              .height = 558
+            },
+            .scale = 1.3763440847396851,
+            .is_primary = TRUE,
+            .is_presentation = FALSE,
+            .monitors = {
+              {
+                .connector = "DP-1",
+                .vendor = "MetaProduct's Inc.",
+                .product = "MetaMonitor",
+                .serial = "0x123456",
+                .mode = {
+                  .width = 1024,
+                  .height = 768,
+                  .refresh_rate = 60.000495910644531
+                }
+              }
+            },
+            .n_monitors = 1,
+          }
+        },
+        .n_logical_monitors = 1
+      }
+    },
+    .n_configurations = 1
+  };
+
+  if (!is_using_monitor_config_manager ())
+    {
+      g_test_skip ("Not using MetaMonitorConfigManager");
+      return;
+    }
+
+  if (!meta_is_stage_views_enabled ())
+    {
+      g_test_skip ("Not using stage views");
+      return;
+    }
+
+  set_custom_monitor_config ("high-precision-fractional-scale.xml");
+
+  check_monitor_configurations (&expect);
+}
+
 static void
 meta_test_monitor_store_mirrored (void)
 {
@@ -806,6 +862,8 @@ init_monitor_store_tests (void)
                    meta_test_monitor_store_scale);
   g_test_add_func ("/backends/monitor-store/fractional-scale",
                    meta_test_monitor_store_fractional_scale);
+  g_test_add_func ("/backends/monitor-store/high-precision-fractional-scale",
+                   meta_test_monitor_store_high_precision_fractional_scale);
   g_test_add_func ("/backends/monitor-store/mirrored",
                    meta_test_monitor_store_mirrored);
   g_test_add_func ("/backends/monitor-store/first-rotated",

src/tests/monitor-unit-tests.c

@@ -3111,6 +3111,108 @@ meta_test_monitor_custom_fractional_scale_config (void)
   check_monitor_configuration (&test_case);
 }
 
+static void
+meta_test_monitor_custom_high_precision_fractional_scale_config (void)
+{
+  MonitorTestCase test_case = {
+    .setup = {
+      .modes = {
+        {
+          .width = 1024,
+          .height = 768,
+          .refresh_rate = 60.000495910644531
+        }
+      },
+      .n_modes = 1,
+      .outputs = {
+        {
+          .crtc = 0,
+          .modes = { 0 },
+          .n_modes = 1,
+          .preferred_mode = 0,
+          .possible_crtcs = { 0 },
+          .n_possible_crtcs = 1,
+          .width_mm = 222,
+          .height_mm = 125
+        },
+      },
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0
+        },
+      },
+      .n_crtcs = 1
+    },
+
+    .expect = {
+      .monitors = {
+        {
+          .outputs = { 0 },
+          .n_outputs = 1,
+          .modes = {
+            {
+              .width = 1024,
+              .height = 768,
+              .crtc_modes = {
+                {
+                  .output = 0,
+                  .crtc_mode = 0
+                }
+              }
+            }
+          },
+          .n_modes = 1,
+          .current_mode = 0,
+          .width_mm = 222,
+          .height_mm = 125,
+        }
+      },
+      .n_monitors = 1,
+      .logical_monitors = {
+        {
+          .monitors = { 0 },
+          .n_monitors = 1,
+          .layout = { .x = 0, .y = 0, .width = 744, .height = 558 },
+          .scale = 1024.0/744.0 /* 1.3763440847396851 */
+        }
+      },
+      .n_logical_monitors = 1,
+      .primary_logical_monitor = 0,
+      .n_outputs = 1,
+      .crtcs = {
+        {
+          .current_mode = 0,
+        }
+      },
+      .n_crtcs = 1,
+      .n_tiled_monitors = 0,
+      .screen_width = 744,
+      .screen_height = 558
+    }
+  };
+  MetaMonitorTestSetup *test_setup;
+
+  if (!is_using_monitor_config_manager ())
+    {
+      g_test_skip ("Not using MetaMonitorConfigManager");
+      return;
+    }
+
+  if (!meta_is_stage_views_enabled ())
+    {
+      g_test_skip ("Not using stage views");
+      return;
+    }
+
+  test_setup = create_monitor_test_setup (&test_case,
+                                          MONITOR_TEST_FLAG_NONE);
+  set_custom_monitor_config ("high-precision-fractional-scale.xml");
+  emulate_hotplug (test_setup);
+
+  check_monitor_configuration (&test_case);
+}
+
 static void
 meta_test_monitor_custom_tiled_config (void)
 {
@@ -4392,6 +4494,8 @@ init_monitor_tests (void)
                    meta_test_monitor_custom_scale_config);
   g_test_add_func ("/backends/monitor/custom/fractional-scale-config",
                    meta_test_monitor_custom_fractional_scale_config);
+  g_test_add_func ("/backends/monitor/custom/high-precision-fractional-scale-config",
+                   meta_test_monitor_custom_high_precision_fractional_scale_config);
   g_test_add_func ("/backends/monitor/custom/tiled-config",
                    meta_test_monitor_custom_tiled_config);
   g_test_add_func ("/backends/monitor/custom/tiled-custom-resolution-config",