Fixes to use atomic rename(2) if possible in nsLocalFile::MoveTo (33098, r=?),

plus a bunch of other fixes and cleanups:

- Fix comment misstatements of fact in nsIFile.idl, improve style slightly.
- Fix typo in comment in nsILocalFile.idl.
- Avoid gratuitous nsCString and nsXPIDLCString copy-constructions, which
  entail malloc'ing, in nsLocalFileUnix.cpp's CopyTo and GetParent methods.
  But do use nsXPIDLCString instead of raw nsMemory::Alloc/Free.
- Get rid of unnecessary mLL_II2L and mLL_L2II macros, use "prlong.h" API only.
  Also use the LL_* macros consistently in case a Unix lacking long long type
  support wants to use this code.
* BTW, the "Date" methods should be renamed to use "Time" instead -- after all
  PRTime is the type, and traditionally "time" refers to the time-number, a
  scalar independent of one's position on the surface of the earth, while
  "date" refers to a struct full of locale-specific information derived from
  time and some "environment" variables such as DST.  Can we rename these
  nsIFile methods before Mozilla 0.9 / Netscape 6?
- Use CHECK_mPath consistently and first, before any assertions relating to
  arguments (which logically come after the 'this' parameter CHECK_mPath is
  making assertions about).
- Use nsCOMPtr for singly-inheriting implementations of XPCOM interfaces, to
  avoid scary-when-scaled 0-refcnt instances from being handled (these all
  got a ref via QI or equivalent soon enough, but you never know).  This also
  removed some naked deletes.
- Canonize all paths copied into mPath to lack trailing slashes, so we don't
  need to strip trailing slashes elsewhere, in higher-frequency methods (you
  set path less often than you get it or a substring of it).
- ssize_t for strlen return values.
- Since shaver used a function pointer to consolidate creat/mkdir logic, but
  didn't fold the necessary close of the new fd returned by non-failing creat
  into the pointed-at function, I did that.
- AppendRelativePath forbids .. as a component (bounded by / or beginning or
  end of string on either side), not just in the middle of fragment (so that
  foo..bar is not an illegal relative pathname -- it should not be).  BTW,
  what the heck is the difference between NS_ERROR_FILE_UNRECOGNIZED_PATH and
  ...INVALID_PATH?
- SetLeafName was overallocating the new pathname buffer by failing to subtract
  the old leafname's length.
- CopyTo was failing to return an NSRESULT_FOR_ERRNO(), it just called that
  macro on a line by itself -- eek!  It also contained redundant if (newFD
  == nsnull) {...} cleanup code, it did a useless PR_GetFileInfo call, and it
  leaked FDs on read or write error.
- Implemented CopyToFollowingLinks as a forwarded call to CopyTo, Unix does
  not support "copying" a symlink via normal file i/o.  Should we instead
  lstat in CopyTo and if a link is the source of the copy, do readlink and
  then symlink?
- Fixed the readlink method (GetTarget) to null-terminate the link string in
  the out parameter (readlink does not do that for you).
- Lots of little nsnull vs. NULL vs. 0, == and != applied to boolean or null
  literals, white-space, indentation, bracing, comment, and sloppy code order
  (e.g., declaring an initialized variable that's not used till after early
  returns) fixes.  Also invert some return logic so that NS_OK is the normal,
  least indented, final return.


git-svn-id: svn://10.0.0.236/trunk@79492 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/xpcom/io/nsIFile.idl

@@ -102,14 +102,15 @@ interface nsIFile : nsISupports
      *
      *   @param newParentDir
      *       This param is the destination directory. If the
-     *       newParentDir is nsnull, copyTo() will simply
-     *       rename the file. If the newParentDir is not
-     *       null and does not exists, an error will be
+     *       newParentDir is null, copyTo() will use the parent
+     *       directory of this file. If the newParentDir is not
+     *       null and is not a directory, an error will be
      *       returned (NS_ERROR_FILE_DESTINATION_NOT_DIR)
      *
      *   @param newName
-     *       This param allows you to specify a new name
-     *       for the file to be copied.  This can be nsnull.
+     *       This param allows you to specify a new name for
+     *       the file to be copied. This param may be null, in
+     *       which case the current leaf name will be used.
      *
      */
     void copyTo(in nsIFile newParentDir, [const] in string newName);
@@ -119,7 +120,9 @@ interface nsIFile : nsISupports
      *  copyToFollowingLinks
      *
      *  This function is identical to copyTo except it, as
-     *  the name implies, follows symbolic links.
+     *  the name implies, follows symbolic links.  Some OSes
+     *  such as Unix and Linux always follow symbolic links
+     *  when copying.
      */
     void copyToFollowingLinks(in nsIFile newParentDir, [const] in string newName);
     void copyToFollowingLinksUnicode(in nsIFile newParentDir, [const] in wstring newName);
@@ -138,14 +141,15 @@ interface nsIFile : nsISupports
      *
      *   @param newParentDir
      *       This param is the destination directory. If the
-     *       newParentDir is nsnull, moveTo() will simply
-     *       rename the file. If the newParentDir is not
-     *       null and does not exists, an error will be
-     *       returned (NS_ERROR_FILE_DESTINATION_NOT_DIR)
+     *       newParentDir is null, moveTo() will rename the file
+     *       within its current directory. If the newParentDir is
+     *       not null and does not name a directory, an error will
+     *       be returned (NS_ERROR_FILE_DESTINATION_NOT_DIR)
      *
      *   @param newName
-     *       This param allows you to specify a new name
-     *       for the file to be moved.  This can be nsnull.
+     *       This param allows you to specify a new name for
+     *       the file to be moved. This param may be null, in
+     *       which case the current leaf name will be used.
      *
      */
     void moveTo(in nsIFile newParentDir, [const] in string newName);
@@ -277,13 +281,13 @@ interface nsIFile : nsISupports
     boolean equals(in nsIFile inFile);
 
     /**
-     * Will determine if the inFile is a descendant
-     * If |recur| is true, it will descend subdirectories looking for
+     * Will determine if inFile is a descendant of this file
+     * If |recur| is true, look in subdirectories too
      */
     boolean contains(in nsIFile inFile, in boolean recur);
 
     /**
-     * Parent will be nsnull when this is at the top of the volume.
+     * Parent will be null when this is at the top of the volume.
      */
     readonly attribute nsIFile parent;
     

mozilla/xpcom/io/nsILocalFile.idl

@@ -52,7 +52,7 @@ interface nsILocalFile : nsIFile
      *   @param filePath       
      *          A string which specifies a full file path to a 
      *          location.  Relative paths will be treated as an
-     *          error (NS_ERROR_FILE_UNRECONGNIZED_PATH).  This
+     *          error (NS_ERROR_FILE_UNRECOGNIZED_PATH).  This
      *          path must in native.
      */
     void initWithPath([const] in string filePath);

mozilla/xpcom/io/nsLocalFileUnix.h

@@ -38,7 +38,7 @@
 #include "nsLocalFile.h"
 #include "nsXPIDLString.h"
 
-#define NSRESULT_FOR_RETURN(ret) (!(ret) ? NS_OK : NSRESULT_FOR_ERRNO())
+#define NSRESULT_FOR_RETURN(ret) (((ret) < 0) ? NSRESULT_FOR_ERRNO() : NS_OK)
 
 inline nsresult
 nsresultForErrno(int err)
@@ -94,6 +94,8 @@ protected:
     
     nsresult CreateAllAncestors(PRUint32 permissions);
     nsresult GetLeafNameRaw(const char **_retval);
+    nsresult GetTargetPathName(nsIFile *newParent, const char *newName,
+                               char **_retval);
 
     void InvalidateCache() { mHaveCachedStat = PR_FALSE; }
 
@@ -109,4 +111,5 @@ protected:
     }
 
 };
+
 #endif /* _nsLocalFileUNIX_H_ */