diff --git a/src/main.rs b/src/main.rs
index 0f20477..d3f76fb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -180,13 +180,14 @@ fn main() -> ResultS<()>
 
    let mut opt: Options = Default::default();
    {
+      let mut ap = ArgumentParser::new();
+
       macro_rules! arg {
-         ($name:expr, $ref:expr, $type:expr, $ap:expr, $desc:expr) => {
-            $ap.refer(&mut $ref).add_option(&[$name], $type, $desc);
+         ($name:expr, $ref:expr, $type:expr, $desc:expr) => {
+            ap.refer(&mut $ref).add_option(&[$name], $type, $desc);
          };
       }
 
-      let mut ap = ArgumentParser::new();
       ap.set_description(env!("CARGO_PKG_DESCRIPTION"));
 
       ap.add_option(&["-v", "--version"],
@@ -198,43 +199,43 @@ fn main() -> ResultS<()>
       ap.refer(&mut opt.inputs)
         .add_argument("inputs", Collect, "Input files");
 
-      arg!("--shp-write-tab", opt.shp_tab, StoreTrue, ap,
+      arg!("--shp-write-tab", opt.shp_tab, StoreTrue,
            "shp: Dump all CLUTs as YAML to standard output");
 
-      arg!("--shp-dump-bitmaps", opt.shp_bmp, StoreTrue, ap,
+      arg!("--shp-dump-bitmaps", opt.shp_bmp, StoreTrue,
            "shp: Dump bitmaps into a folder");
 
-      arg!("--shp-dump-more-bitmaps", opt.shp_bmp_all, StoreTrue, ap,
+      arg!("--shp-dump-more-bitmaps", opt.shp_bmp_all, StoreTrue,
            "shp: Dump all color variations of each bitmap");
 
-      arg!("--shp-write-frm", opt.shp_frm, StoreTrue, ap,
+      arg!("--shp-write-frm", opt.shp_frm, StoreTrue,
            "shp: Dump all frames as YAML to standard output");
 
-      arg!("--shp-write-seq", opt.shp_seq, StoreTrue, ap,
+      arg!("--shp-write-seq", opt.shp_seq, StoreTrue,
            "shp: Dump all sequences as YAML to standard output");
 
-      arg!("--snd-write", opt.snd_write, StoreTrue, ap,
+      arg!("--snd-write", opt.snd_write, StoreTrue,
            "snd: Dump all sound headers as YAML to standard output");
 
-      arg!("--snd-dump", opt.snd_dump, StoreTrue, ap,
+      arg!("--snd-dump", opt.snd_dump, StoreTrue,
            "snd: Dump all sounds to WAVE files");
 
-      arg!("--wad-dump-all", opt.wad_all, StoreTrue, ap,
+      arg!("--wad-dump-all", opt.wad_all, StoreTrue,
            "wad: Dump all chunks into a folder");
 
-      arg!("--wad-dump-unknown", opt.wad_unknown, StoreTrue, ap,
+      arg!("--wad-dump-unknown", opt.wad_unknown, StoreTrue,
            "wad: Dump all unknown chunks into a folder");
 
-      arg!("--wad-write-header", opt.wad_header, StoreTrue, ap,
+      arg!("--wad-write-header", opt.wad_header, StoreTrue,
            "wad: Dump header info as YAML to standard output");
 
-      arg!("--wad-write-chunks", opt.wad_c_temp, Store, ap,
+      arg!("--wad-write-chunks", opt.wad_c_temp, Store,
            "wad: Dump specified chunks in various formats");
 
-      arg!("--out-dir", opt.out_dir, Store, ap,
+      arg!("--out-dir", opt.out_dir, Store,
            "Sets output directory for dump options");
 
-      arg!("--out-debug", opt.out_debug, StoreTrue, ap,
+      arg!("--out-debug", opt.out_debug, StoreTrue,
            "Writes debugging output rather than YAML");
 
       ap.parse_args_or_exit();
diff --git a/src/marathon/shp.rs b/src/marathon/shp.rs
index 4b542f9..4c7827c 100644
--- a/src/marathon/shp.rs
+++ b/src/marathon/shp.rs
@@ -23,13 +23,8 @@ fn color(b: &[u8], clut: &mut [ColorShp]) -> ResultS<()>
    }?;
 
    let cr = ColorShp::Opaque{r, g, b, l};
-
-   if let Some(cl) = clut.get_mut(i as usize) {
-      *cl = cr;
-      Ok(())
-   } else {
-      bail!("bad index");
-   }
+   clut[i as usize] = cr;
+   Ok(())
 }
 
 fn color_tables(b: &[u8],
@@ -40,10 +35,6 @@ fn color_tables(b: &[u8],
 {
    let end = tab_num * clr_num * 8;
 
-   if b.len() < tab_ofs + end {
-      bail!("not enough data");
-   }
-
    let b = &b[tab_ofs..tab_ofs + end];
 
    let mut v = vec![vec![ColorShp::Translucent; clr_num]; tab_num];
@@ -97,7 +88,7 @@ fn bitmap(b: &[u8]) -> ResultS<Bitmap>
 
          p += 4;
 
-         if lst < fst || fst > pitch || lst > pitch || p + end >= b.len() {
+         if lst < fst || fst > pitch || lst > pitch || b.len() < p + end {
             bail!("invalid compressed scanline");
          }
 
@@ -115,7 +106,7 @@ fn bitmap(b: &[u8]) -> ResultS<Bitmap>
       }
    } else {
       // simple copy
-      if p + width * height >= b.len() {
+      if b.len() < p + width * height {
          bail!("invalid scanline");
       }
 
@@ -226,21 +217,13 @@ pub fn read_shapes(b: &[u8]) -> ResultS<Vec<CollectionDef>>
       }
 
       let c_lo = if lo_ofs != u32::max_value() as usize {
-         if b.len() < lo_ofs + lo_len {
-            bail!("not enough data");
-         } else {
-            Some(collection(&b[lo_ofs..lo_ofs + lo_len])?)
-         }
+         Some(collection(&b[lo_ofs..lo_ofs + lo_len])?)
       } else {
          None
       };
 
       let c_hi = if hi_ofs != u32::max_value() as usize {
-         if b.len() < hi_ofs + hi_len {
-            bail!("not enough data");
-         } else {
-            Some(collection(&b[hi_ofs..hi_ofs + hi_len])?)
-         }
+         Some(collection(&b[hi_ofs..hi_ofs + hi_len])?)
       } else {
          None
       };
diff --git a/src/marathon/wad.rs b/src/marathon/wad.rs
index a277e37..3121692 100644
--- a/src/marathon/wad.rs
+++ b/src/marathon/wad.rs
@@ -51,10 +51,6 @@ impl Wad<'_>
 
          let index = if !is_old {index} else {i as u16};
 
-         if offset + size > b.len() {
-            bail!("not enough data for entry");
-         }
-
          let cnkdata = &b[offset..offset + size];
          let chunks  = get_chunks(cnkdata, cnksize)?;
          let appdata = &b[p..p + appsize];