Add header stripping

src/lib.rs

@@ -3,6 +3,7 @@ extern crate crc;
 extern crate libc;
 extern crate libz_sys;
 
+use std::collections::HashMap;
 use std::collections::HashSet;
 use std::fs;
 use std::fs::File;
@@ -73,7 +74,9 @@ pub fn optimize(filepath: &Path, opts: &Options) -> Result<(), String> {
         println!("    IDAT size = {} bytes", idat_original_size);
         println!("    File size = {} bytes", file_original_size);
     }
-    // TODO: Bit depth/palette reduction
+    // TODO: Color space reduction
+    // TODO: 16-bit Bit depth reduction
+    // TODO: Palette bit depth reduction
     //
     // TODO: Apply interlacing changes
     //
@@ -127,7 +130,10 @@ pub fn optimize(filepath: &Path, opts: &Options) -> Result<(), String> {
         }
     }
 
-    // TODO: Perform stripping
+    if opts.strip {
+        // Strip headers
+        png.aux_headers = HashMap::new();
+    }
 
     let output_data = png.output();
     if file_original_size <= output_data.len() && !opts.force {

tests/oxipng.rs

@@ -129,3 +129,30 @@ fn reduce_palette_png() {
     assert!(png.ihdr_data.bit_depth == png::BitDepth::Eight);
     assert!(png.palette.unwrap().len() == 43 * 3);
 }
+
+#[test]
+fn strip_headers() {
+    let input = PathBuf::from("tests/files/test_rgb.png");
+    let mut opts = get_opts(&input);
+    opts.strip = true;
+    let output = opts.out_file.clone();
+
+    match oxipng::optimize(&input, &opts) {
+        Ok(_) => (),
+        Err(x) => panic!(x.to_owned())
+    };
+    assert!(output.exists());
+
+    let png = match png::PngData::new(&output) {
+        Ok(x) => {
+            remove_file(output).ok();
+            x
+        },
+        Err(x) => {
+            remove_file(output).ok();
+            panic!(x.to_owned())
+        },
+    };
+
+    assert!(!png.aux_headers.contains_key("tEXt"));
+}