3 files changed, 50 insertions, 2 deletions
diff --git a/drivers/unix/dir_access_unix.cpp b/drivers/unix/dir_access_unix.cpp
index 095991e27b..46efb45934 100644
--- a/drivers/unix/dir_access_unix.cpp
+++ b/drivers/unix/dir_access_unix.cpp
@@ -38,9 +38,11 @@
 #include "core/templates/list.h"
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/ioctl.h>
 #include <sys/statvfs.h>
 
 #ifdef HAVE_MNTENT
@@ -488,6 +490,27 @@ bool DirAccessUnix::is_hidden(const String &p_name) {
 	return p_name != "." && p_name != ".." && p_name.begins_with(".");
 }
 
+bool DirAccessUnix::is_case_sensitive(const String &p_path) const {
+#if defined(LINUXBSD_ENABLED)
+	String f = p_path;
+	if (!f.is_absolute_path()) {
+		f = get_current_dir().path_join(f);
+	}
+	f = fix_path(f);
+
+	int fd = ::open(f.utf8().get_data(), O_RDONLY | O_NONBLOCK);
+	if (fd) {
+		long flags = 0;
+		if (ioctl(fd, _IOR('f', 1, long), &flags) >= 0) {
+			::close(fd);
+			return !(flags & 0x40000000 /* FS_CASEFOLD_FL */);
+		}
+		::close(fd);
+	}
+#endif
+	return true;
+}
+
 DirAccessUnix::DirAccessUnix() {
 	dir_stream = nullptr;
 	_cisdir = false;
diff --git a/drivers/unix/dir_access_unix.h b/drivers/unix/dir_access_unix.h
index 68ad869003..8d13ff1fa8 100644
--- a/drivers/unix/dir_access_unix.h
+++ b/drivers/unix/dir_access_unix.h
@@ -82,6 +82,8 @@ public:
 	virtual String read_link(String p_file) override;
 	virtual Error create_link(String p_source, String p_target) override;
 
+	virtual bool is_case_sensitive(const String &p_path) const override;
+
 	virtual uint64_t get_space_left() override;
 
 	virtual String get_filesystem_type() const override;
diff --git a/drivers/unix/os_unix.cpp b/drivers/unix/os_unix.cpp
index 581daaca05..51ea9234d4 100644
--- a/drivers/unix/os_unix.cpp
+++ b/drivers/unix/os_unix.cpp
@@ -85,6 +85,12 @@
 #define RTLD_DEEPBIND 0
 #endif
 
+#ifndef SANITIZERS_ENABLED
+#define GODOT_DLOPEN_MODE RTLD_NOW | RTLD_DEEPBIND
+#else
+#define GODOT_DLOPEN_MODE RTLD_NOW
+#endif
+
 #if defined(MACOS_ENABLED) || (defined(__ANDROID_API__) && __ANDROID_API__ >= 28)
 // Random location for getentropy. Fitting.
 #include <sys/random.h>
@@ -650,7 +656,9 @@ Error OS_Unix::open_dynamic_library(const String p_path, void *&p_library_handle
 		path = get_executable_path().get_base_dir().path_join("../lib").path_join(p_path.get_file());
 	}
 
-	p_library_handle = dlopen(path.utf8().get_data(), RTLD_NOW | RTLD_DEEPBIND);
+	ERR_FAIL_COND_V(!FileAccess::exists(path), ERR_FILE_NOT_FOUND);
+
+	p_library_handle = dlopen(path.utf8().get_data(), GODOT_DLOPEN_MODE);
 	ERR_FAIL_NULL_V_MSG(p_library_handle, ERR_CANT_OPEN, vformat("Can't open dynamic library: %s. Error: %s.", p_path, dlerror()));
 
 	if (r_resolved_path != nullptr) {
@@ -745,12 +753,27 @@ String OS_Unix::get_executable_path() const {
 		return OS::get_executable_path();
 	}
 	return b;
-#elif defined(__OpenBSD__) || defined(__NetBSD__)
+#elif defined(__OpenBSD__)
 	char resolved_path[MAXPATHLEN];
 
 	realpath(OS::get_executable_path().utf8().get_data(), resolved_path);
 
 	return String(resolved_path);
+#elif defined(__NetBSD__)
+	int mib[4] = { CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME };
+	char buf[MAXPATHLEN];
+	size_t len = sizeof(buf);
+	if (sysctl(mib, 4, buf, &len, nullptr, 0) != 0) {
+		WARN_PRINT("Couldn't get executable path from sysctl");
+		return OS::get_executable_path();
+	}
+
+	// NetBSD does not always return a normalized path. For example if argv[0] is "./a.out" then executable path is "/home/netbsd/./a.out". Normalize with realpath:
+	char resolved_path[MAXPATHLEN];
+
+	realpath(buf, resolved_path);
+
+	return String(resolved_path);
 #elif defined(__FreeBSD__)
 	int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1 };
 	char buf[MAXPATHLEN];