Don't print empty lines in single threaded mode.

Fixes #99.

src/main.rs

@@ -22,7 +22,7 @@ extern crate winapi;
 
 use std::error::Error;
 use std::fs::File;
-use std::io::{self, Write};
+use std::io;
 use std::path::Path;
 use std::process;
 use std::result;
@@ -157,31 +157,28 @@ fn run_one_thread(args: Arc<Args>) -> Result<u64> {
         match_count: 0,
     };
     let paths = args.paths();
-    let filesep = args.file_separator();
     let mut term = args.stdout();
 
     let mut paths_searched: u64 = 0;
     for p in paths {
         if p == Path::new("-") {
-            if worker.match_count > 0 {
-                if let Some(ref sep) = filesep {
-                    let _ = term.write_all(sep);
-                    let _ = term.write_all(b"\n");
-                }
-            }
             paths_searched += 1;
             let mut printer = args.printer(&mut term);
+            if worker.match_count > 0 {
+                if let Some(sep) = args.file_separator() {
+                    printer = printer.file_separator(sep);
+                }
+            }
             worker.do_work(&mut printer, WorkReady::Stdin);
         } else {
             for ent in try!(args.walker(p)) {
-                if worker.match_count > 0 {
-                    if let Some(ref sep) = filesep {
-                        let _ = term.write_all(sep);
-                        let _ = term.write_all(b"\n");
-                    }
-                }
                 paths_searched += 1;
                 let mut printer = args.printer(&mut term);
+                if worker.match_count > 0 {
+                    if let Some(sep) = args.file_separator() {
+                        printer = printer.file_separator(sep);
+                    }
+                }
                 let file = match File::open(ent.path()) {
                     Ok(file) => file,
                     Err(err) => {

src/out.rs

@@ -48,8 +48,6 @@ impl Out {
 
     /// If set, the separator is printed between matches from different files.
     /// By default, no separator is printed.
-    ///
-    /// If sep is empty, then no file separator is printed.
     pub fn file_separator(mut self, sep: Vec<u8>) -> Out {
         self.file_separator = Some(sep);
         self

src/printer.rs

@@ -25,6 +25,8 @@ pub struct Printer<W> {
     /// printed via the match directly, but occasionally we need to insert them
     /// ourselves (for example, to print a context separator).
     eol: u8,
+    /// A file separator to show before any matches are printed.
+    file_separator: Option<Vec<u8>>,
     /// Whether to show file name as a heading or not.
     ///
     /// N.B. If with_filename is false, then this setting has no effect.
@@ -51,6 +53,7 @@ impl<W: Terminal + Send> Printer<W> {
             column: false,
             context_separator: "--".to_string().into_bytes(),
             eol: b'\n',
+            file_separator: None,
             heading: false,
             line_per_match: false,
             quiet: false,
@@ -79,6 +82,13 @@ impl<W: Terminal + Send> Printer<W> {
         self
     }
 
+    /// If set, the separator is printed before any matches. By default, no
+    /// separator is printed.
+    pub fn file_separator(mut self, sep: Vec<u8>) -> Printer<W> {
+        self.file_separator = Some(sep);
+        self
+    }
+
     /// Whether to show file name as a heading or not.
     ///
     /// N.B. If with_filename is false, then this setting has no effect.
@@ -230,6 +240,7 @@ impl<W: Terminal + Send> Printer<W> {
         column: Option<u64>,
     ) {
         if self.heading && self.with_filename && !self.has_printed {
+            self.write_file_sep();
             self.write_heading(path.as_ref());
         } else if !self.heading && self.with_filename {
             self.write_path(path.as_ref());
@@ -284,6 +295,7 @@ impl<W: Terminal + Send> Printer<W> {
         line_number: Option<u64>,
     ) {
         if self.heading && self.with_filename && !self.has_printed {
+            self.write_file_sep();
             self.write_heading(path.as_ref());
         } else if !self.heading && self.with_filename {
             self.write_path(path.as_ref());
@@ -355,4 +367,15 @@ impl<W: Terminal + Send> Printer<W> {
         let eol = self.eol;
         self.write(&[eol]);
     }
+
+    fn write_file_sep(&mut self) {
+        if self.quiet {
+            return;
+        }
+        if let Some(ref sep) = self.file_separator {
+            self.has_printed = true;
+            let _ = self.wtr.write_all(sep);
+            let _ = self.wtr.write_all(b"\n");
+        }
+    }
 }

tests/tests.rs

@@ -54,6 +54,13 @@ fn path(unix: &str) -> String {
     }
 }
 
+fn sort_lines(lines: &str) -> String {
+    let mut lines: Vec<String> =
+        lines.trim().lines().map(|s| s.to_owned()).collect();
+    lines.sort();
+    format!("{}\n", lines.join("\n"))
+}
+
 sherlock!(single_file, |wd: WorkDir, mut cmd| {
     let lines: String = wd.stdout(&mut cmd);
     let expected = "\
@@ -716,6 +723,18 @@ clean!(regression_93, r"(\d{1,3}\.){3}\d{1,3}", ".",
     assert_eq!(lines, "foo:192.168.1.1\n");
 });
 
+// See: https://github.com/BurntSushi/ripgrep/issues/99
+clean!(regression_99, "test", ".",
+|wd: WorkDir, mut cmd: Command| {
+    wd.create("foo1", "test");
+    wd.create("foo2", "zzz");
+    wd.create("bar", "test");
+    cmd.arg("-j1").arg("--heading");
+
+    let lines: String = wd.stdout(&mut cmd);
+    assert_eq!(sort_lines(&lines), sort_lines("bar\ntest\n\nfoo1\ntest\n"));
+});
+
 // See: https://github.com/BurntSushi/ripgrep/issues/105
 clean!(regression_105_part1, "test", ".", |wd: WorkDir, mut cmd: Command| {
     wd.create("foo", "zztest");