Merge pull request #33 from niklasf/cap-field-sizes

also cap mtime and mode in header

fuzz/src/lib.rs

@@ -1,4 +1,5 @@
 use arbitrary::{Arbitrary, Unstructured};
+use std::cmp::min;
 
 #[derive(Clone, Default, Debug, Eq, PartialEq, Arbitrary)]
 pub struct Model {
@@ -76,29 +77,33 @@ impl Arbitrary<'_> for Identifier {
     }
 }
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug, Eq, Arbitrary)]
 struct Mode(u32);
 
-impl Arbitrary<'_> for Mode {
-    fn arbitrary(u: &mut Unstructured<'_>) -> arbitrary::Result<Self> {
-        u32::arbitrary(u).map(|v| Mode(v & 0o7777))
+impl PartialEq for Mode {
+    fn eq(&self, other: &Mode) -> bool {
+        self.0 & 0o7777_7777 == other.0 & 0o7777_7777
     }
 }
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug, Eq, Arbitrary)]
 struct Timestamp(u64);
 
-impl Arbitrary<'_> for Timestamp {
-    fn arbitrary(u: &mut Unstructured<'_>) -> arbitrary::Result<Self> {
-        u.int_in_range(0..=999_999_999_999).map(Timestamp) // TODO: Deal with entire range
+impl PartialEq for Timestamp {
+    fn eq(&self, other: &Timestamp) -> bool {
+        min(self.0, 999_999_999_999) == min(other.0, 999_999_999_999)
     }
 }
 
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+#[derive(Copy, Clone, Debug, Eq, Arbitrary)]
 struct Uid(u32);
 
-impl Arbitrary<'_> for Uid {
-    fn arbitrary(u: &mut Unstructured<'_>) -> arbitrary::Result<Self> {
-        u.int_in_range(0..=999_999).map(Uid) // TODO: Deal with entire range (#29)
+impl PartialEq for Uid {
+    fn eq(&self, other: &Uid) -> bool {
+        let mut left = self.0.to_string();
+        left.truncate(6);
+        let mut right = other.0.to_string();
+        right.truncate(6);
+        left == right
     }
 }

src/header.rs

@@ -1,3 +1,4 @@
+use std::cmp::min;
 use std::collections::HashMap;
 use std::fs::Metadata;
 use std::io::{self, Error, ErrorKind, Read, Result, Write};
@@ -244,10 +245,10 @@ impl Header {
                 writer,
                 "#1/{:<13}{:<12}{:<6.6}{:<6.6}{:<8o}{:<10}`",
                 padded_length,
-                self.mtime,
+                cap_mtime(self.mtime),
                 self.uid.to_string(),
                 self.gid.to_string(),
-                self.mode,
+                cap_mode(self.mode),
                 self.size + padded_length as u64
             )?;
             writer.write_all(&self.identifier)?;
@@ -258,10 +259,10 @@ impl Header {
             writeln!(
                 writer,
                 "{:<12}{:<6.6}{:<6.6}{:<8o}{:<10}`",
-                self.mtime,
+                cap_mtime(self.mtime),
                 self.uid.to_string(),
                 self.gid.to_string(),
-                self.mode,
+                cap_mode(self.mode),
                 self.size
             )?;
         }
@@ -287,16 +288,24 @@ impl Header {
         writeln!(
             writer,
             "{:<12}{:<6.6}{:<6.6}{:<8o}{:<10}`",
-            self.mtime,
+            cap_mtime(self.mtime),
             self.uid.to_string(),
             self.gid.to_string(),
-            self.mode,
+            cap_mode(self.mode),
             self.size
         )?;
         Ok(())
     }
 }
 
+fn cap_mtime(mtime: u64) -> u64 {
+    min(mtime, 999_999_999_999) // Closest representable timestamp
+}
+
+fn cap_mode(mode: u32) -> u32 {
+    mode & 0o7777_7777 // Preserve as many bits as possible
+}
+
 fn parse_number(field_name: &str, bytes: &[u8], radix: u32) -> Result<u64> {
     if let Ok(string) = str::from_utf8(bytes) {
         if let Ok(value) = u64::from_str_radix(string.trim_end(), radix) {