ignore: fix improper hidden filtering

This commit fixes a bug where `rg --hidden .` would behave differently
with respect to ignore filtering than `rg --hidden ./`. In particular,
this was due to a bug where the directory name `.` caused the leading
`.` in a hidden directory to get stripped, which in turn caused the
ignore rules to fail.

Fixes #807

2 files changed, 30 insertions, 2 deletions

diff --git a/ignore/src/gitignore.rs b/ignore/src/gitignore.rs
index a21afa55..7e7233d6 100644
--- a/ignore/src/gitignore.rs
+++ b/ignore/src/gitignore.rs
@@ -66,6 +66,12 @@ impl Glob {
     pub fn is_only_dir(&self) -> bool {
         self.is_only_dir
     }
+
+    /// Returns true if and only if this glob has a `**/` prefix.
+    fn has_doublestar_prefix(&self) -> bool {
+        self.actual.starts_with("**/")
+        || (self.actual == "**" && self.is_only_dir)
+    }
 }
 
 /// Gitignore is a matcher for the globs in one or more gitignore files
@@ -278,7 +284,10 @@ impl Gitignore {
         // BUT, a file name might not have any directory components to it,
         // in which case, we don't want to accidentally strip any part of the
         // file name.
-        if !is_file_name(path) {
+        //
+        // As an additional special case, if the root is just `.`, then we
+        // shouldn't try to strip anything, e.g., when path begins with a `.`.
+        if self.root != Path::new(".") && !is_file_name(path) {
             if let Some(p) = strip_prefix(&self.root, path) {
                 path = p;
                 // If we're left with a leading slash, get rid of it.
@@ -454,7 +463,7 @@ impl GitignoreBuilder {
         // prefix.
         if !literal_separator {
             // ... but only if we don't already have a **/ prefix.
-            if !(glob.actual.starts_with("**/") || (glob.actual == "**" && glob.is_only_dir)) {
+            if !glob.has_doublestar_prefix() {
                 glob.actual = format!("**/{}", glob.actual);
             }
         }
@@ -620,6 +629,12 @@ mod tests {
     ignored!(ig29, ROOT, "node_modules/ ", "node_modules", true);
     ignored!(ig30, ROOT, "**/", "foo/bar", true);
     ignored!(ig31, ROOT, "path1/*", "path1/foo");
+    ignored!(ig32, ROOT, ".a/b", ".a/b");
+    ignored!(ig33, "./", ".a/b", ".a/b");
+    ignored!(ig34, ".", ".a/b", ".a/b");
+    ignored!(ig35, "./.", ".a/b", ".a/b");
+    ignored!(ig36, "././", ".a/b", ".a/b");
+    ignored!(ig37, "././.", ".a/b", ".a/b");
 
     not_ignored!(ignot1, ROOT, "amonths", "months");
     not_ignored!(ignot2, ROOT, "monthsa", "months");
diff --git a/tests/tests.rs b/tests/tests.rs
index e88756dc..0e144d19 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -1232,6 +1232,19 @@ clean!(regression_599, "^$", "input.txt", |wd: WorkDir, mut cmd: Command| {
     assert_eq!(expected, lines);
 });
 
+// See: https://github.com/BurntSushi/ripgrep/issues/807
+clean!(regression_807, "test", ".", |wd: WorkDir, mut cmd: Command| {
+    wd.create(".gitignore", ".a/b");
+    wd.create_dir(".a/b");
+    wd.create_dir(".a/c");
+    wd.create(".a/b/file", "test");
+    wd.create(".a/c/file", "test");
+
+    cmd.arg("--hidden");
+    let lines: String = wd.stdout(&mut cmd);
+    assert_eq!(lines, format!("{}:test\n", path(".a/c/file")));
+});
+
 // See: https://github.com/BurntSushi/ripgrep/issues/1
 clean!(feature_1_sjis, "Шерлок Холмс", ".", |wd: WorkDir, mut cmd: Command| {
     let sherlock =