Fix handling of potentially unsupported time metadata

- Checking on a directory doesn’t tell us if supported elsewhere
(some filesystems, like tmpfs, don’t support created time)
- We want to be able to display a column even if some subfiles or
subdirectories don’t support it

So now if unsupported a time of zero is used, and displayed as `-`

src/fs/file.rs

@@ -328,7 +328,10 @@ impl<'dir> File<'dir> {
 
     /// This file’s last modified timestamp.
     pub fn modified_time(&self) -> Duration {
-        self.metadata.modified().unwrap().duration_since(UNIX_EPOCH).unwrap()
+        match self.metadata.modified() {
+            Ok(system_time) => system_time.duration_since(UNIX_EPOCH).unwrap(),
+            Err(_) => Duration::new(0, 0),
+        }
     }
 
     /// This file’s last changed timestamp.
@@ -338,12 +341,18 @@ impl<'dir> File<'dir> {
 
     /// This file’s last accessed timestamp.
     pub fn accessed_time(&self) -> Duration {
-        self.metadata.accessed().unwrap().duration_since(UNIX_EPOCH).unwrap()
+        match self.metadata.accessed() {
+            Ok(system_time) => system_time.duration_since(UNIX_EPOCH).unwrap(),
+            Err(_) => Duration::new(0, 0),
+        }
     }
 
     /// This file’s created timestamp.
     pub fn created_time(&self) -> Duration {
-        self.metadata.created().unwrap().duration_since(UNIX_EPOCH).unwrap()
+        match self.metadata.created() {
+            Ok(system_time) => system_time.duration_since(UNIX_EPOCH).unwrap(),
+            Err(_) => Duration::new(0, 0),
+        }
     }
 
     /// This file’s ‘type’.
@@ -460,41 +469,6 @@ impl<'dir> FileTarget<'dir> {
 }
 
 
-pub enum PlatformMetadata {
-    ModifiedTime,
-    ChangedTime,
-    AccessedTime,
-    CreatedTime,
-}
-
-impl PlatformMetadata {
-    pub fn check_supported(&self) -> Result<(), Misfire> {
-        use std::env::temp_dir;
-        let result = match self {
-            // Call the functions that return a Result to see if it works
-            PlatformMetadata::AccessedTime => metadata(temp_dir()).unwrap().accessed(),
-            PlatformMetadata::ModifiedTime => metadata(temp_dir()).unwrap().modified(),
-            PlatformMetadata::CreatedTime  => metadata(temp_dir()).unwrap().created(),
-            // We use the Unix API so we know it’s not available elsewhere
-            PlatformMetadata::ChangedTime => {
-                if cfg!(target_family = "unix") {
-                    return Ok(())
-                } else {
-                    return Err(Misfire::Unsupported(
-                        // for consistency, this error message similar to the one Rust
-                        // use when created time is not available
-                        "status modified time is not available on this platform currently".to_string()));
-                }
-            },
-        };
-        match result {
-            Ok(_) => Ok(()),
-            Err(err) => Err(Misfire::Unsupported(err.to_string()))
-        }
-    }
-}
-
-
 /// More readable aliases for the permission bits exposed by libc.
 #[allow(trivial_numeric_casts)]
 mod modes {

src/fs/mod.rs

@@ -2,7 +2,7 @@ mod dir;
 pub use self::dir::{Dir, DotFilter};
 
 mod file;
-pub use self::file::{File, FileTarget, PlatformMetadata};
+pub use self::file::{File, FileTarget};
 
 pub mod feature;
 pub mod fields;

src/options/filter.rs

@@ -1,6 +1,6 @@
 //! Parsing the options for `FileFilter`.
 
-use fs::{DotFilter, PlatformMetadata};
+use fs::DotFilter;
 use fs::filter::{FileFilter, SortField, SortCase, IgnorePatterns, GitIgnore};
 
 use options::{flags, Misfire};
@@ -67,23 +67,7 @@ impl SortField {
             _ => return Err(Misfire::BadArgument(&flags::SORT, word.into()))
         };
 
-        match SortField::to_platform_metadata(field) {
-            Some(m) => match m.check_supported() {
-                Ok(_) => Ok(field),
-                Err(misfire) => Err(misfire),
-            },
-            None => Ok(field),
-        }
-    }
-
-    fn to_platform_metadata(field: Self) -> Option<PlatformMetadata> {
-        match field {
-            SortField::ModifiedDate => Some(PlatformMetadata::ModifiedTime),
-            SortField::ChangedDate  => Some(PlatformMetadata::ChangedTime),
-            SortField::AccessedDate => Some(PlatformMetadata::AccessedTime),
-            SortField::CreatedDate  => Some(PlatformMetadata::CreatedTime),
-            _ => None
-        }
+        Ok(field)
     }
 }
 

src/options/view.rs

@@ -6,7 +6,6 @@ use output::time::TimeFormat;
 use options::{flags, Misfire, Vars};
 use options::parser::MatchedFlags;
 
-use fs::PlatformMetadata;
 use fs::feature::xattr;
 
 
@@ -344,17 +343,6 @@ impl TimeTypes {
             TimeTypes::default()
         };
 
-        let mut fields = vec![];
-        if time_types.modified { fields.push(PlatformMetadata::ModifiedTime); }
-        if time_types.changed  { fields.push(PlatformMetadata::ChangedTime); }
-        if time_types.accessed { fields.push(PlatformMetadata::AccessedTime); }
-        if time_types.created  { fields.push(PlatformMetadata::CreatedTime); }
-
-        for field in fields {
-            if let Err(misfire) = field.check_supported() {
-                return Err(misfire);
-            }
-        }
         Ok(time_types)
     }
 }
@@ -542,15 +530,9 @@ mod test {
         test!(time_a:    TimeTypes <- ["-t", "acc"];           Both => Ok(TimeTypes { modified: false, changed: false, accessed: true,  created: false }));
 
         // Created
-        #[cfg(not(target_os = "linux"))]
         test!(cr:        TimeTypes <- ["--created"];           Both => Ok(TimeTypes { modified: false, changed: false, accessed: false, created: true  }));
-        #[cfg(target_os = "linux")]
-        test!(cr:        TimeTypes <- ["--created"];           Both => err Misfire::Unsupported("creation time is not available on this platform currently".to_string()));
-        #[cfg(not(target_os = "linux"))]
         test!(c:         TimeTypes <- ["-U"];                  Both => Ok(TimeTypes { modified: false, changed: false, accessed: false, created: true  }));
-        #[cfg(not(target_os = "linux"))]
         test!(time_cr:   TimeTypes <- ["--time=created"];      Both => Ok(TimeTypes { modified: false, changed: false, accessed: false, created: true  }));
-        #[cfg(not(target_os = "linux"))]
         test!(t_cr:      TimeTypes <- ["-tcr"];                Both => Ok(TimeTypes { modified: false, changed: false, accessed: false, created: true  }));
 
         // Multiples

src/output/time.rs

@@ -129,6 +129,9 @@ impl DefaultFormat {
 
     #[allow(trivial_numeric_casts)]
     fn format_local(&self, time: Duration) -> String {
+        if time.as_nanos() == 0 {
+            return "-".to_string();
+        }
         let date = LocalDateTime::at(time.as_secs() as i64);
 
         if self.is_recent(date) {
@@ -141,6 +144,10 @@ impl DefaultFormat {
 
     #[allow(trivial_numeric_casts)]
     fn format_zoned(&self, time: Duration, zone: &TimeZone) -> String {
+        if time.as_nanos() == 0 {
+            return "-".to_string();
+        }
+
         let date = zone.to_zoned(LocalDateTime::at(time.as_secs() as i64));
 
         if self.is_recent(date) {