Fix segmentation fault caused by infinite recursion and unsafe array … (#213)

* Fix segmentation fault caused by infinite recursion and unsafe array access

- Fix infinite recursion in ProcessUtils::runCommand(): skip javaExe() call
  when searching for java via which/where commands to prevent recursive loop
- Fix unsafe array access in VersionResolveWorker::resolve(): add isEmpty()
  check before accessing result.output[0] when checking Java version

The segfault occurred because runCommand() called javaExe() to set JAVA_HOME,
which called findInPath() that called runCommand(which, java) again,
creating an infinite recursion loop.

* Removed accident build directory

Author: babkinvanya

sources/processutils.cpp

@@ -139,8 +139,12 @@ ProcessResult ProcessUtils::runCommand(const QString &exe, const QStringList &ar
     }
 
     // Set JAVA_HOME for all commands when Java location is known
+    // But skip if we're searching for java itself (which/where commands)
     QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
-    QString javaPath = ProcessUtils::javaExe(); // Get Java path from settings
+    QString javaPath;
+    if (actualExe != "which" && actualExe != "where") {
+        javaPath = ProcessUtils::javaExe(); // Get Java path from settings
+    }
     if (!javaPath.isEmpty()) {
         QFileInfo javaInfo(javaPath);
         QString javaHome = javaInfo.absolutePath();
@@ -167,8 +171,12 @@ ProcessResult ProcessUtils::runCommand(const QString &exe, const QStringList &ar
     process.start(actualExe, actualArgs, QIODevice::ReadOnly);
 #else
     // Set JAVA_HOME for all commands when Java location is known
+    // But skip if we're searching for java itself (which/where commands)
     QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
-    QString javaPath = ProcessUtils::javaExe(); // Get Java path from settings
+    QString javaPath;
+    if (exe != "which" && exe != "where") {
+        javaPath = ProcessUtils::javaExe(); // Get Java path from settings
+    }
     if (!javaPath.isEmpty()) {
         QFileInfo javaInfo(javaPath);
         QString javaHome = javaInfo.absolutePath();

sources/versionresolveworker.cpp

@@ -25,7 +25,7 @@ void VersionResolveWorker::resolve()
 #ifdef QT_DEBUG
         qDebug() << "Java returned code" << result.code;
 #endif
-        if (result.code == 0) {
+        if ((result.code == 0) && !result.output.isEmpty()) {
 #ifdef QT_DEBUG
             qDebug() << "Java returned" << result.output[0];
 #endif