fix(#14): add LibRawGuard RAII Drop guard for automatic memory cleanup

src/main.rs

@@ -71,6 +71,28 @@ fn libraw_error_string(code: c_int) -> &'static str {
     }
 }
 
+/// RAII guard for libraw memory cleanup.
+/// Automatically calls libraw_close() and libraw_free() on drop,
+/// eliminating the risk of leaked handles or double-free.
+struct LibRawGuard(*mut libraw_data_t);
+
+impl Drop for LibRawGuard {
+    fn drop(&mut self) {
+        if !self.0.is_null() {
+            unsafe {
+                libraw_close(self.0);
+                libraw_free(self.0);
+            }
+        }
+    }
+}
+
+impl LibRawGuard {
+    fn ptr(&self) -> *mut libraw_data_t {
+        self.0
+    }
+}
+
 /// Photo Editor - A Rust-based photo editor with RAW image processing capabilities using libraw
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None)]
@@ -226,12 +248,14 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     println!("\n[INFO] Attempting RAW image processing with libraw integration...");
 
-    // Initialize libraw
+    // Initialize libraw with RAII guard for automatic cleanup
-    let lr = unsafe { libraw_init(LIBRAW_OPTIONS_NONE) };
+    let lr_raw = unsafe { libraw_init(LIBRAW_OPTIONS_NONE) };
-    if lr.is_null() {
+    if lr_raw.is_null() {
         eprintln!("Error: Failed to initialize libraw");
         return Err("Failed to initialize libraw".into());
     }
+    let lr_guard = LibRawGuard(lr_raw);
+    let lr = lr_guard.ptr();
 
     // Open the RAW file
     let input_cstr = CString::new(input_path.to_string_lossy().as_bytes())
@@ -240,7 +264,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     if ret != LIBRAW_SUCCESS {
         eprintln!("Error: Failed to open file: {}", libraw_error_string(ret));
-        unsafe { libraw_close(lr) };
         return Err("Failed to open file".into());
     }
 
@@ -250,7 +273,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let ret = unsafe { libraw_unpack(lr) };
     if ret != LIBRAW_SUCCESS {
         eprintln!("Error: Failed to unpack RAW data: {}", libraw_error_string(ret));
-        unsafe { libraw_close(lr) };
         return Err("Failed to unpack RAW data".into());
     }
 
@@ -265,7 +287,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let ret = unsafe { libraw_dcraw_process(lr) };
     if ret != LIBRAW_SUCCESS {
         eprintln!("Error: Failed to process image: {}", libraw_error_string(ret));
-        unsafe { libraw_close(lr) };
         return Err("Failed to process image".into());
     }
 
@@ -317,17 +338,11 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     if ret != LIBRAW_SUCCESS {
         eprintln!("Error: Failed to write output file: {}", libraw_error_string(ret));
-        unsafe { libraw_close(lr) };
         return Err("Failed to write output file".into());
     }
 
     println!("[INFO] Processed image written to disk");
 
-    // Clean up
-    unsafe {
-        libraw_close(lr);
-    }
-
     println!("\n[SUCCESS] Photo editing completed successfully with libraw integration!");
     println!(
         "[NOTICE] The edited image has been saved as: {}",