Add test that asks for more context than is available.

tests/test_search_epub.cpp

@@ -88,8 +88,7 @@ SCENARIO("Searching EPUB files works")
     GIVEN("Our test EPUB3 file")
     {
         fs::path epubfile{"test.epub3"};
-        std::setlocale(LC_CTYPE,
+        std::setlocale(LC_CTYPE, ""); // Needed for utf-8 support in libarchive.
-                       ""); // Needed for utf-8 support in libarchive.
         bool exception{false};
 
         REQUIRE(fs::exists(epubfile));
@@ -161,6 +160,32 @@ SCENARIO("Searching EPUB files works")
                                R"(media-type="application/xhtml+xml")");
                 }
             }
+
+            WHEN("We search for for a phrase at the beginning of the file "
+                 "and specify a very high context")
+            {
+                try
+                {
+                    opts.context = 69069;
+                    matches = epubgrep::search::search(epubfile, "Test for",
+                                                       opts);
+                }
+                catch (const std::exception &)
+                {
+                    exception = true;
+                }
+
+                THEN("No exception is thrown")
+                AND_THEN("It returns the match correctly")
+                {
+                    REQUIRE_FALSE(exception);
+                    REQUIRE(matches.at(0).filepath_inside == "start.xhtml");
+                    REQUIRE(matches.at(0).text == "Test for");
+                    REQUIRE(matches.at(0).headline.empty());
+                    REQUIRE(matches.at(0).context.first.empty());
+                    REQUIRE(*matches.at(0).context.second.rbegin() == '.');
+                }
+            }
         }
     }
 }