Fixed handling of filter regexps.

env/Cargo.toml

@@ -17,3 +17,7 @@ path = ".."
 
 [dependencies]
 regex = "0.1"
+
+[[test]]
+name = "regexp_filter"
+harness = false

env/src/lib.rs

@@ -309,7 +309,7 @@ impl Log for Logger {
         }
 
         if let Some(filter) = self.filter.as_ref() {
-            if filter.is_match(&*record.args().to_string()) {
+            if !filter.is_match(&*record.args().to_string()) {
                 return;
             }
         }

env/tests/regexp_filter.rs

@@ -0,0 +1,51 @@
+#[macro_use] extern crate log;
+extern crate env_logger;
+
+use std::process;
+use std::env;
+use std::str;
+
+fn main() {
+    if env::var("LOG_REGEXP_TEST").ok() == Some(String::from("1")) {
+        child_main();
+    } else {
+        parent_main()
+    }
+}
+
+fn child_main() {
+    env_logger::init().unwrap();
+    info!("XYZ Message");
+}
+
+fn run_child(rust_log: String) -> bool {
+    let exe = env::current_exe().unwrap();
+    let out = process::Command::new(exe)
+        .env("LOG_REGEXP_TEST", "1")
+        .env("RUST_LOG", rust_log)
+        .output()
+        .unwrap_or_else(|e| panic!("Unable to start child process: {}", e));
+    str::from_utf8(out.stderr.as_ref()).unwrap().contains("XYZ Message")
+}
+
+fn assert_message_printed(rust_log: &str) {
+    if !run_child(rust_log.to_string()) {
+        panic!("RUST_LOG={} should allow the test log message", rust_log)
+    }
+}
+
+fn assert_message_not_printed(rust_log: &str) {
+    if run_child(rust_log.to_string()) {
+        panic!("RUST_LOG={} should not allow the test log message", rust_log)
+    }
+}
+
+fn parent_main() {
+    // test normal log severity levels
+    assert_message_printed("info");
+    assert_message_not_printed("warn");
+
+    // test of regular expression filters
+    assert_message_printed("info/XYZ");
+    assert_message_not_printed("info/XXX");
+}