From eefb254de16a9336525ebbfb2e72aa760d215a7e Mon Sep 17 00:00:00 2001
From: Ronny Dudeck <rdu@paeffgen.com>
Date: Wed, 6 May 2026 08:20:08 +0200
Subject: [PATCH] config(legacy): null-check getConfigValueSafeDevice in
 getDevice* getters

getConfigValueSafeDevice can return nullptr when:
- the device has no matching special config entry, and
- the fallback string is empty (default for getDevice* caller)

This caused a null dereference in getDeviceInt, getDeviceFloat,
getDeviceVec, and getDeviceString when called for devices without
a explicit config block. InputManager.cpp:1170 (keyboard tags)
and :1301 (mouse tags) hit this on startup for any device that
doesn't has a device { name = ...; tags = ...; } entry.

The tags feature was added in r320, exposing this latent bugs.

Fix by storing the pointer local and returning type-appropriate
defaults (0, 0.F, {0,0}, "") when nullptr.

Fixes: 497b48e ("config: add device tags (#13728)")
---
 src/config/legacy/ConfigManager.cpp | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/config/legacy/ConfigManager.cpp b/src/config/legacy/ConfigManager.cpp
index e4c485e03..95a93cb80 100644
--- a/src/config/legacy/ConfigManager.cpp
+++ b/src/config/legacy/ConfigManager.cpp
@@ -1134,25 +1134,34 @@ bool CConfigManager::deviceConfigExplicitlySet(const std::string& dev, const std
 }
 
 int CConfigManager::getDeviceInt(const std::string& dev, const std::string& v, const std::string& fallback) {
-    return std::any_cast<Hyprlang::INT>(getConfigValueSafeDevice(dev, v, fallback)->getValue());
+    const auto VAL = getConfigValueSafeDevice(dev, v, fallback);
+    return VAL ? std::any_cast<Hyprlang::INT>(VAL->getValue()) : 0;
 }
 
 float CConfigManager::getDeviceFloat(const std::string& dev, const std::string& v, const std::string& fallback) {
-    return std::any_cast<Hyprlang::FLOAT>(getConfigValueSafeDevice(dev, v, fallback)->getValue());
+    const auto VAL = getConfigValueSafeDevice(dev, v, fallback);
+    return VAL ? std::any_cast<Hyprlang::FLOAT>(VAL->getValue()) : 0.F;
 }
 
 Vector2D CConfigManager::getDeviceVec(const std::string& dev, const std::string& v, const std::string& fallback) {
-    auto vec = std::any_cast<Hyprlang::VEC2>(getConfigValueSafeDevice(dev, v, fallback)->getValue());
+    const auto VAL = getConfigValueSafeDevice(dev, v, fallback);
+    if (!VAL)
+        return {0, 0};
+    auto vec = std::any_cast<Hyprlang::VEC2>(VAL->getValue());
     return {vec.x, vec.y};
 }
 
 std::string CConfigManager::getDeviceString(const std::string& dev, const std::string& v, const std::string& fallback) {
-    auto VAL = std::string{std::any_cast<Hyprlang::STRING>(getConfigValueSafeDevice(dev, v, fallback)->getValue())};
-
-    if (VAL == STRVAL_EMPTY)
+    const auto VAL = getConfigValueSafeDevice(dev, v, fallback);
+    if (!VAL)
         return "";
 
-    return VAL;
+    auto STR = std::string{std::any_cast<Hyprlang::STRING>(VAL->getValue())};
+
+    if (STR == STRVAL_EMPTY)
+        return "";
+
+    return STR;
 }
 
 SConfigOptionReply CConfigManager::getConfigValue(const std::string& val) {