Disable Unicode mode for literal regex.

When ripgrep detects a literal, it emits them as raw hex escaped byte
sequences to Regex::new. This permits literal optimizations for arbitrary
byte sequences (i.e., possibly invalid UTF-8). The problem is that
Regex::new interprets hex escaped byte sequences as *Unicode codepoints*
by default, but we want them to actually stand for their raw byte values.
Therefore, disable Unicode mode.

This is OK, since the regex is composed entirely of literals and literal
extraction does Unicode case folding.

Fixes #251

2 files changed, 3 insertions, 4 deletions

diff --git a/grep/src/literals.rs b/grep/src/literals.rs
index d931f135..3e68d24e 100644
--- a/grep/src/literals.rs
+++ b/grep/src/literals.rs
@@ -79,12 +79,12 @@ impl LiteralSets {
             debug!("required literals found: {:?}", req_lits);
             let alts: Vec<String> =
                 req_lits.into_iter().map(|x| bytes_to_regex(x)).collect();
-            Some(RegexBuilder::new(&alts.join("|")))
+            Some(RegexBuilder::new(&alts.join("|")).unicode(false))
         } else if lit.is_empty() {
             None
         } else {
             debug!("required literal found: {:?}", show(lit));
-            Some(RegexBuilder::new(&bytes_to_regex(lit)))
+            Some(RegexBuilder::new(&bytes_to_regex(&lit)).unicode(false))
         }
     }
 }
diff --git a/grep/src/search.rs b/grep/src/search.rs
index 850c8d62..cf1a4c3f 100644
--- a/grep/src/search.rs
+++ b/grep/src/search.rs
@@ -167,14 +167,13 @@ impl GrepBuilder {
     /// Creates a new regex from the given expression with the current
     /// configuration.
     fn regex(&self, expr: &Expr) -> Result<Regex> {
-        self.regex_build(RegexBuilder::new(&expr.to_string()))
+        self.regex_build(RegexBuilder::new(&expr.to_string()).unicode(true))
     }
 
     /// Builds a new regex from the given builder using the caller's settings.
     fn regex_build(&self, builder: RegexBuilder) -> Result<Regex> {
         builder
             .multi_line(true)
-            .unicode(true)
             .size_limit(self.opts.size_limit)
             .dfa_size_limit(self.opts.dfa_size_limit)
             .compile()