[qt] fix various crashes due to invalid/corrupted/outdated settings (#4070)

lots of "out of index" errors :)

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4070
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

3 files changed, 77 insertions, 0 deletions

diff --git a/tools/README.md b/tools/README.md
index 367a00f246..d4f5aa1baa 100644
--- a/tools/README.md
+++ b/tools/README.md
@@ -28,6 +28,8 @@ Tools for Eden and other subprojects. When adding new scripts please use `#!/bin
 - `clang-format.sh`: Runs `clang-format` on the entire codebase.
     * Requires: clang
 - `find-unused-strings.sh`: Find any unused strings in the Android app (XML -> Kotlin).
+- `cpp-lint.sh`: Homemade dumb C++ linter.
+- `fuzzsettings.cpp`: Fuzz settings files.
 
 ## Android
 It's recommended to run these scritps after almost any Android change, as they are relatively fast and important both for APK bloat and CI.
diff --git a/tools/fuzzsettings.cpp b/tools/fuzzsettings.cpp
new file mode 100644
index 0000000000..e9685ce9f4
--- /dev/null
+++ b/tools/fuzzsettings.cpp
@@ -0,0 +1,63 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <cstdio>
+#include <cstdlib>
+#include <cctype>
+#include <cstring>
+#include <ctime>
+#include <string>
+#include <string_view>
+
+int main(int argc, char *argv[]) {
+    std::srand(unsigned(std::time(nullptr)));
+
+    FILE *fp = std::fopen(argv[1], "rt");
+    if (fp) {
+        char line[BUFSIZ];
+        while (std::fgets(line, sizeof(line), fp)) {
+            if (line[0] == '[') {
+                std::printf("%s", line);
+            } else if (std::isspace(line[0])) {
+                std::printf("%s", line);
+            } else {
+                char *p = std::strchr(line, '=');
+                if (std::strstr(line, "\\default") == nullptr) {
+                    // not default
+                    *p = '\0';
+                    std::string new_line{line};
+                    std::string value{p + 1};
+                    if (value == "true" || value == "false") {
+                        new_line += std::string{} + "=TreufLAlse857874FJJakshjryiu475" + '\n';
+                    } else if (std::isdigit(value[0])) {
+                        if (new_line == "size"
+                        || std::strstr(new_line.c_str(), "entries\\size") != nullptr
+                        || std::strstr(new_line.c_str(), "\\size")) {
+                            new_line += "=-1\n";
+                        } else {
+                            new_line += '=' + std::to_string(int(std::rand())) + '\n';
+                        }
+                    } else {
+                        std::string_view const cset{"03832///1/1/.1/1./1./1./1.1/.1194573290uwmgjouidyhiomHMNIODASJK,POF MSHDVLJPOIuksdtpsunmghns"};
+                        std::string rst{"000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"};
+                        for (size_t i = 0; i < rst.size(); ++i)
+                            rst[i] = cset[std::rand() % cset.size()];
+
+                        //new_line += "=\"" + rst + "\"";
+                        new_line += "=" + value;
+                    }
+                    std::printf("%s", new_line.c_str());
+                } else {
+                    // yes default
+                    *p = '\0';
+                    std::string new_line{line};
+                    std::string value{p + 1};
+                    new_line += "=false\n";
+                    std::printf("%s", new_line.c_str());
+                }
+            }
+        }
+        std::fclose(fp);
+    }
+    return 0;
+}
diff --git a/tools/fuzzsettings.sh b/tools/fuzzsettings.sh
new file mode 100755
index 0000000000..7cf613dc3d
--- /dev/null
+++ b/tools/fuzzsettings.sh
@@ -0,0 +1,12 @@
+#!/bin/sh -ex
+
+# SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+ROOTDIR=$(CDPATH='' cd -- "$(dirname -- "$0")/" && pwd)
+
+touch "$2"
+
+c++ "$ROOTDIR/fuzzsettings.cpp" -o fuzzsettings
+./fuzzsettings "$1" >"$2"
+rm fuzzsettings