[commit: packages/filepath] master: Insert slash when first argument to joinDrive does not end with one (c986cde)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/filepath

On branch  : master
Link       : http://git.haskell.org/packages/filepath.git/commitdiff/c986cde979992074dabda71088474630f459cd13

>---------------------------------------------------------------

commit c986cde979992074dabda71088474630f459cd13
Author: Thomas Miedema <thomasmiedema at gmail.com>
Date:   Thu Oct 23 18:23:56 2014 +0200

    Insert slash when first argument to joinDrive does not end with one
    
    Before:
    joinDrive "/foo" "bar" == "/foobar"
    
    After:
    joinDrive "/foo" "bar" == "/foo/bar"
    
    The first argument to `joinDrive` should arguably always be a drive. On Posix
    this means it should be, and thus end with, a single slash. It is currently
    undocumented what should happen when it doesn't end with a slash (throw an
    exception?). Since it is unlikely anyone is relying on the original behavior,
    this change is hopefully ok to make.
    
    The reason for this change is to make `joinDrive` similar in semantics to
    `combineAlways`.


>---------------------------------------------------------------

c986cde979992074dabda71088474630f459cd13
 System/FilePath/Internal.hs | 5 ++---
 changelog.md                | 3 +++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/System/FilePath/Internal.hs b/System/FilePath/Internal.hs
index e48d01b..1e2cdc9 100644
--- a/System/FilePath/Internal.hs
+++ b/System/FilePath/Internal.hs
@@ -383,12 +383,11 @@ readDriveShareName name = addSlash a b
 -- > Windows: joinDrive "\\\\share" "foo" == "\\\\share\\foo"
 -- > Windows: joinDrive "/:" "foo" == "/:\\foo"
 joinDrive :: FilePath -> FilePath -> FilePath
-joinDrive a b | isPosix = a ++ b
-              | null a = b
+joinDrive a b | null a = b
               | null b = a
               | hasTrailingPathSeparator a = a ++ b
               | otherwise = case a of
-                                [a1,':'] | isLetter a1 -> a ++ b
+                                [a1,':'] | isWindows && isLetter a1 -> a ++ b
                                 _ -> a ++ [pathSeparator] ++ b
 
 -- | Get the drive from a filepath.
diff --git a/changelog.md b/changelog.md
index b037c48..f79c011 100644
--- a/changelog.md
+++ b/changelog.md
@@ -4,6 +4,9 @@
 
   * Bundled with GHC 7.10.1
 
+  * Semantic change: `joinDrive "/foo" "bar"` now returns `"/foo/bar"`,
+    instead of `"/foobar"`.
+
   * Bug fix: `isDrive ""` now retuns `False`, instead of `True`.
 
   * Bug fix: on Windows, `dropTrailingPathSeparator "/"` now returns `"/"`