test(html): render an image, and one of them in the dark

test/data.cmake

@@ -7,7 +7,7 @@
 odr_test_data(
         PATH "input/odr-public"
         URL "https://github.com/opendocument-app/OpenDocument.test.git"
-        REVISION "77ed98d72075bbd375be328b7232f40568a32563")
+        REVISION "1ad8965bfc65529a715d5b0e39743292e879329e")
 
 odr_test_data(
         PATH "input/odr-private"
@@ -17,7 +17,7 @@ odr_test_data(
 odr_test_data(
         PATH "reference-output/odr-public"
         URL "https://github.com/opendocument-app/OpenDocument.test.output.git"
-        REVISION "9f41493817bd7d33ea6aae8dc63011e46f87f1d6")
+        REVISION "cf8f1e19ae5d70f433114c5ca29716931c29ebfe")
 
 odr_test_data(
         PATH "reference-output/odr-private"

test/src/html_output_test.cpp

@@ -275,14 +275,16 @@ std::vector<std::pair<std::string, ConfigVariant>> list_variant_cases() {
       // renders one.
       {"odr-private/pdf/978-3-030-65771-0.pdf", single},
 
-      // One file per view honoring a color scheme. The pdf view honors none,
-      // and no test file reaches the image view at all.
+      // One file per view honoring a color scheme. The pdf view honors none.
       {"odr-public/odt/style-various-1.odt", dark},
       {"odr-public/odp/style-various-1.odp", dark},
       {"odr-public/ods/style-border-1.ods", dark},
       {"odr-public/txt/lorem ipsum.txt", dark},
       {"odr-public/zip/small.zip", dark},
       {"odr-private/otf/OpenSans-Regular.otf", dark},
+      // The image view paints the ground the picture sits on and nothing else,
+      // so the file that shows it is one with transparency.
+      {"odr-public/png/tango-example-icons.png", dark},
       // `system` writes what `dark` writes, wrapped in a media query; one file
       // pins that wrapper.
       {"odr-public/txt/lorem ipsum.txt", system},

test/src/internal/magic_test.cpp

@@ -8,6 +8,8 @@
 #include <gtest/gtest.h>
 
 #include <sstream>
+#include <string>
+#include <tuple>
 
 using namespace odr;
 using namespace odr::internal;
@@ -58,6 +60,45 @@ TEST(magic, wpd) {
             "application/vnd.wordperfect");
 }
 
+/// What an encoder actually writes, rather than the signature a table says it
+/// should: a jpeg names itself with whichever application marker it happens to
+/// carry, and a webp only after its RIFF form tag.
+TEST(magic, images) {
+  for (const auto &[path, type, mimetype] :
+       {std::tuple{"odr-public/png/tango-example-icons.png",
+                   FileType::portable_network_graphics, "image/png"},
+        std::tuple{"odr-public/jpg/fantastic-landscape.jpg", FileType::jpeg,
+                   "image/jpeg"},
+        std::tuple{"odr-public/gif/knights-tour.gif",
+                   FileType::graphics_interchange_format, "image/gif"},
+        std::tuple{"odr-public/bmp/tango-example-icons.bmp",
+                   FileType::bitmap_image_file, "image/bmp"},
+        std::tuple{"odr-public/webp/lorine-niedecker.webp", FileType::webp,
+                   "image/webp"}}) {
+    const File file(TestData::test_file_path(path));
+
+    EXPECT_EQ(magic::file_type(*file.impl()), type) << path;
+    EXPECT_EQ(magic::mimetype(file.disk_path().value(), Logger::null()),
+              mimetype)
+        << path;
+  }
+}
+
+/// An svg carries no signature at all - it is named by parsing it, and only the
+/// open strategy does that.
+TEST(magic, svg) {
+  for (const std::string path :
+       {"odr-public/svg/rotating-snakes.svg",
+        "odr-public/svg/civitas-schinesghe-emblem.svg"}) {
+    const File file(TestData::test_file_path(path));
+
+    EXPECT_EQ(magic::file_type(*file.impl()), FileType::unknown) << path;
+    EXPECT_EQ(magic::mimetype(file.disk_path().value(), Logger::null()),
+              "image/svg+xml")
+        << path;
+  }
+}
+
 namespace {
 
 FileType detect(const std::string &head) {