Fix several typos in comments

src/liblog/lib.rs

@@ -137,7 +137,7 @@
 //! includes 'foo'.
 //! * `info/f.o` turns on all info logging where the log message includes 'foo',
 //! 'f1o', 'fao', etc.
-//! * `hello=debug/foo*foo` turns on debug logging for 'hello' where the the log
+//! * `hello=debug/foo*foo` turns on debug logging for 'hello' where the log
 //! message includes 'foofoo' or 'fofoo' or 'fooooooofoo', etc.
 //! * `error,hello=warn/[0-9] scopes` turn on global error logging and also warn for
 //!  hello. In both cases the log message must include a single digit number

src/libregex/re.rs

@@ -558,7 +558,7 @@ pub struct NoExpand<'t>(pub &'t str);
 /// Replacer describes types that can be used to replace matches in a string.
 pub trait Replacer {
     /// Returns a possibly owned string that is used to replace the match
-    /// corresponding the the `caps` capture group.
+    /// corresponding to the `caps` capture group.
     ///
     /// The `'a` lifetime refers to the lifetime of a borrowed string when
     /// a new owned string isn't needed (e.g., for `NoExpand`).

src/librustc/middle/traits/select.rs

@@ -345,7 +345,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         // matches this obligation, then we can assume that the
         // obligation is satisfied for now (still all other conditions
         // must be met of course). One obvious case this comes up is
-        // marker traits like `Send`. Think of a a linked list:
+        // marker traits like `Send`. Think of a linked list:
         //
         //    struct List<T> { data: T, next: Option<Box<List<T>>> {
         //

src/libstd/collections/hash/table.rs

@@ -716,7 +716,7 @@ impl<'a, K, V> Iterator<RawBucket<K, V>> for RawBuckets<'a, K, V> {
 }
 
 /// An iterator that moves out buckets in reverse order. It leaves the table
-/// in an an inconsistent state and should only be used for dropping
+/// in an inconsistent state and should only be used for dropping
 /// the table's remaining entries. It's used in the implementation of Drop.
 struct RevMoveBuckets<'a, K, V> {
     raw: RawBucket<K, V>,

src/libstd/os.rs

@@ -77,7 +77,7 @@ const BUF_BYTES : uint = 2048u;
 /// # Failure
 ///
 /// Fails if the current working directory value is invalid:
-/// Possibles cases:
+/// Possible cases:
 ///
 /// * Current directory does not exist.
 /// * There are insufficient permissions to access the current directory.