[PATCH] canonicalize: fix // handling

[Eric Blake]

On Cygwin, and other platforms where // is detected as distinct
from / at configure time, the canonicalize routines were incorrectly
treating all instances of multiple leading slashes as //.
See also coreutils bug http://debbugs.gnu.org/10472

* lib/canonicalize.c (canonicalize_filename_mode): Don't convert
/// to //, since only // is special.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog          |    6 ++++++
 lib/canonicalize.c |   12 +++++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 4bbe447..a9aa40a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2012-02-04  Eric Blake  <address@hidden>
+
+       canonicalize: fix // handling
+       * lib/canonicalize.c (canonicalize_filename_mode): Don't convert
+       /// to //, since only // is special.
+
 2012-02-04  Bruno Haible  <address@hidden>

        ioctl: Fix test failure on native Windows.
diff --git a/lib/canonicalize.c b/lib/canonicalize.c
index d3e5645..ed094b7 100644
--- a/lib/canonicalize.c
+++ b/lib/canonicalize.c
@@ -145,7 +145,7 @@ canonicalize_filename_mode (const char *name, 
canonicalize_mode_t can_mode)
       rname_limit = rname + PATH_MAX;
       rname[0] = '/';
       dest = rname + 1;
-      if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/')
+      if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/' && name[2] != '/')
         *dest++ = '/';
     }

@@ -169,7 +169,7 @@ canonicalize_filename_mode (const char *name, 
canonicalize_mode_t can_mode)
           if (dest > rname + 1)
             while ((--dest)[-1] != '/');
           if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
-              && *dest == '/')
+              && *dest == '/' && dest[1] != '/')
             dest++;
         }
       else
@@ -267,7 +267,8 @@ canonicalize_filename_mode (const char *name, 
canonicalize_mode_t can_mode)
               if (buf[0] == '/')
                 {
                   dest = rname + 1;     /* It's an absolute symlink */
-                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && buf[1] == '/')
+                  if (DOUBLE_SLASH_IS_DISTINCT_ROOT
+                      && buf[1] == '/' && buf[2] != '/')
                     *dest++ = '/';
                 }
               else
@@ -277,7 +278,7 @@ canonicalize_filename_mode (const char *name, 
canonicalize_mode_t can_mode)
                   if (dest > rname + 1)
                     while ((--dest)[-1] != '/');
                   if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
-                      && *dest == '/')
+                      && *dest == '/' && dest[1] != '/')
                     dest++;
                 }

@@ -295,7 +296,8 @@ canonicalize_filename_mode (const char *name, 
canonicalize_mode_t can_mode)
     }
   if (dest > rname + 1 && dest[-1] == '/')
     --dest;
-  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && *dest == '/')
+  if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
+      && *dest == '/' && dest[1] != '/')
     dest++;
   *dest = '\0';
   if (rname_limit != dest + 1)
-- 
1.7.7.6