fix mac_roman_cstr API (should never fail)

Cargo.toml

@@ -18,6 +18,7 @@ members = ["source/leela", "source/tycho"]
 bitflags = "1.0"
 failure  = {version = "0.1", features = ["std"]}
 serde    = {version = "1.0", features = ["derive"]}
+memchr   = "2.0"
 
 [profile.dev]
 opt-level = 1

source/durandal/text.rs

@@ -1,7 +1,5 @@
 //! Text conversion utilities.
 
-use crate::durandal::err::*;
-
 /// Formats a binary size string for any given number.
 ///
 /// # Examples
@@ -103,14 +101,17 @@ pub fn mac_roman_conv(s: &[u8]) -> String
 /// ```
 /// use maraiah::durandal::text::mac_roman_cstr;
 ///
-/// assert_eq!(mac_roman_cstr(b"I\xd5ve awaken\0ed").unwrap(), "I’ve awaken");
+/// assert_eq!(mac_roman_cstr(b"I\xd5ve awaken\0ed"), "I’ve awaken");
+/// assert_eq!(mac_roman_cstr(b"I\xd5ve awaken\0"),   "I’ve awaken");
+/// assert_eq!(mac_roman_cstr(b"I\xd5ve awaken"),     "I’ve awaken");
 /// ```
-pub fn mac_roman_cstr(s: &[u8]) -> ResultS<String>
+#[inline]
+pub fn mac_roman_cstr(s: &[u8]) -> String
 {
-   if let Some(s) = s.split(|&n| n == 0).nth(0) {
-      Ok(mac_roman_conv(s))
+   if let Some(n) = memchr::memchr(0, s) {
+      mac_roman_conv(&s[..n])
    } else {
-      bail!("no null in C string");
+      mac_roman_conv(s)
    }
 }
 

source/marathon/map.rs

@@ -55,7 +55,7 @@ pub fn read_minf(b: &[u8]) -> ResultS<Minf>
       skypict_id = u16[4];
       miss_flags = u16[6];
       envi_flags = u16[8];
-      level_name = mac_roman_cstr[18..84];
+      level_name = mac_roman_cstr[18..84] no_try;
       entr_flags = u32[84];
    }
 
@@ -425,7 +425,7 @@ pub fn read_note(b: &[u8]) -> ResultS<(Note, usize)>
       72, BE in b =>
       pos  = read_point[2..6];
       poly = u16[6];
-      text = mac_roman_cstr[8..72];
+      text = mac_roman_cstr[8..72] no_try;
    }
 
    Ok((Note{pos, poly, text}, 72))

source/marathon/trm.rs

@@ -83,7 +83,7 @@ pub fn read_term(b: &[u8]) -> ResultS<(Terminal, usize)>
       let beg   = grp.beg;
       let len   = grp.len;
       let text = ok!(text.get(beg..beg + len), "bad offset")?;
-      let text = mac_roman_cstr(text)?;
+      let text = mac_roman_cstr(text);
 
       groups.push(Group{flags, ttype, lines, text});
    }

source/marathon/wad.rs

@@ -105,7 +105,7 @@ pub fn read_wad(b: &[u8]) -> ResultS<Wad>
       128, BE in b =>
       ver_wad  = u16[0];
       ver_dat  = u16[2];
-      name     = mac_roman_cstr[4..68];
+      name     = mac_roman_cstr[4..68] no_try;
       siz_app  = u16[78] usize;
       siz_wcnk = u16[80] usize;
       siz_went = u16[82] usize;