Library: a cartridge system's archives are games whatever else its core runs

The content scan counted a system's .zip and .7z as games only when none of
its cores took a .cue or .chd, so a core that also runs a disc system hid a
cartridge system's archives: Genesis Plus GX (Sega CD) for the Mega Drive,
Master System, SG-1000 and Game Gear, PicoDrive (Sega CD) for the 32X,
Beetle PCE (the PC Engine CD) for the PC Engine and SuperGrafx. Their
archived games were in neither ES-DE nor the WebUI's library. Whether a
system's archives are games now goes by the system: the disc systems (psx,
ps2, psp, saturn, dreamcast, segacd, pcfx, 3do, neogeocd, gc, wii) keep
theirs out, as before, since RetroArch extracts only the file it loads and a
.cue's tracks would be left behind.

Evidence: tests/ps5_library_test.c, an archived game in an ES-DE megadrive
folder whose core also takes cue and chd (counted; it was not before this
change: the test failed on the game count) beside an archived PlayStation
disc (still left out): python3 -m unittest tests.test_ps5_library OK. On
the console (evidence/esde-folder-names): ES-DE's library went from 28
systems and 255 games to 34 and 317 with the same 325 game backups, the six
systems above among the new ones. tools/verify.sh: all five gates PASS.

src/ps5_library.c

@@ -1364,8 +1364,10 @@ static void scan_root(struct loading *loading, const char *root, const char *fir
             continue; /* no core for it */
         /* RetroArch opens a .zip or .7z itself for a core that does not take one, so a
          * cartridge system's archives are games. A disc system's are not: an archived
-         * disc is a .cue and its tracks, and RetroArch extracts only the file it loads. */
-        if (!list_has(scanning.extensions, "cue") && !list_has(scanning.extensions, "chd"))
+         * disc is a .cue and its tracks, and RetroArch extracts only the file it loads.
+         * Which one a system is goes by the system, not by its core: Genesis Plus GX also
+         * takes Sega CD's .cue, and the Mega Drive's archives are still games. */
+        if (!list_has("psx|ps2|psp|saturn|dreamcast|segacd|pcfx|3do|neogeocd|gc|wii", platform))
             add_extensions(scanning.extensions, sizeof(scanning.extensions), "zip|7z");
         char path[PS5_LIBRARY_PATH_MAX];
         if (!joined(path, sizeof(path), root, listing.names[i]))

tests/ps5_library_test.c

@@ -298,6 +298,9 @@ int main(int argc, char **argv)
     }
     core(dir, "dosbox_pure", "DOS", "zip|dosz|exe|com|bat|iso|cue");
     core(dir, "scummvm", "ScummVM", "scummvm");
+    /* a cartridge system whose core also runs a disc system (Sega CD) */
+    core(dir, "genesis_plus_gx", "Sega - Mega Drive - Genesis|Sega - Mega-CD - Sega CD",
+         "md|bin|cue|chd");
     const char *content_folders[] = {"content",
                                      "content/ATARI 2600",
                                      "content/ATARI 2600/Hacks",
@@ -310,6 +313,8 @@ int main(int argc, char **argv)
                                      "content/ScummVM/Mansion/game",
                                      "content/My Stuff",
                                      "content/Saturn",
+                                     "content/megadrive",
+                                     "content/psx",
                                      "usb",
                                      "usb/Atari 2600"};
     for (size_t i = 0; i < sizeof(content_folders) / sizeof(content_folders[0]); i++)
@@ -336,6 +341,8 @@ int main(int argc, char **argv)
                                    "content/Saturn/game.cue",
                                    "usb/Atari 2600/River Run.a26",
                                    "content/3DO/Archived Disc.7z",
+                                   "content/megadrive/Racer.7z",
+                                   "content/psx/Archived Disc.7z",
                                    "usb/loose.a26"};
     for (size_t i = 0; i < sizeof(content_files) / sizeof(content_files[0]); i++)
     {
@@ -348,12 +355,16 @@ int main(int argc, char **argv)
     const char *const roots[] = {content_root, usb_root, NULL};
     assert(ps5_library_load_content(&library, playlists, info, cores, roots) == 0);
     /* The playlists' nine, and: Quest, Jungle Jump, River Run (the drive), the 3DO game's
-     * .cue, SHOOTER.EXE, Platform.zip and Mansion (Quest.zip though Stella takes no .zip: a
-     * cartridge system's archives are RetroArch's to open). Not: the 3DO's archived disc
-     * (a disc system's archive), readme.txt, the firmware (by the info's
+     * .cue, SHOOTER.EXE, Platform.zip, Mansion and Racer.7z (Quest.zip though Stella takes no
+     * .zip: a cartridge system's archives are RetroArch's to open, and Racer.7z though its core
+     * also runs Sega CD discs). Not: the 3DO's and PlayStation's archived discs (a disc
+     * system's archives), readme.txt, the firmware (by the info's
      * names, a variant of one, [BIOS]), the .iso behind the .cue, SETUP.EXE, SHOOTER.WAD,
      * dosbox.conf, My Stuff (no platform), Saturn (no core), a file at a drive's top. */
-    assert(library.game_count == 9 + 7);
+    assert(library.game_count == 9 + 8);
+    const struct ps5_library_system *megadrive = system_of(&library, "genesis");
+    assert(megadrive && megadrive->game_count == 1 &&
+           strstr(library.games[megadrive->first_game].path, "megadrive/Racer.7z"));
     const struct ps5_library_system *atari = system_of(&library, "atari2600");
     assert(atari && atari->game_count == 3 && strcmp(atari->folder, "/") != 0);
     const struct ps5_library_system *panasonic = system_of(&library, "3do");