Request to improve DailyRollingFileAppender handling of errors during log rotation.  If an error occur,

	P1.	Old logs [to archive] can be lost.  Can occur if scheduled-file=name [to archive to] cannot be deleted during rotation

	P2.	It can end up infinite looping if ErrorHandler itself uses DailyRollingFileAppender

To address above issues, I'm currently use customized version of DailyRollingFileAppender with the following changes:

	C1.	If cannot delete scheduled-file-name, then continue appending to existing file (i.e., don't rotate)

	C2.	Defer invocating ErrorHandler until very end of rollOver() method.

i.e.,  Change Log4j v1.2.15 from

	void rollOver() throws IOException {
		...

		if (target.exists()) {
			target.delete();
		}

		File file = new File(fileName);
		boolean result = file.renameTo(target);
		if(result) {
			LogLog.debug(fileName +" -> "+ scheduledFilename);
		} else {
			LogLog.error("Failed to rename ["+fileName+"] to ["+scheduledFilename+"].");
		}

		try {
			// This will also close the file. This is OK since multiple
			// close operations are safe.
			this.setFile(fileName, false, this.bufferedIO, this.bufferSize);
		}
		catch(IOException e) {
			errorHandler.error("setFile("+fileName+", false) call failed.");
		}

		...
	}

to

	void rollOver() throws IOException {
		...

		List<String> errMsgs = new LinkedList<String>();
		boolean result = true;

		if (target.exists()) {
			result = target.delete();
		}

		if (! result) {
			errMsgs.add("Failed to delete [" + scheduledFilename + "].  Log file will not be rolled over!");
		} else {
			File file = new File(fileName);
			result = file.renameTo(target);
			if(result) {
				LogLog.debug(fileName +" -> "+ scheduledFilename);
			} else {
				errMsgs.add("Failed to rename ["+fileName+"] to ["+scheduledFilename+"].  Log file will not be rolled over!");
			}
		}

		try {
			this.setFile(
					fileName,
					// Append if rollover [to schedule file] failed, else overwrite
					! result,
					this.bufferedIO,
					this.bufferSize);

			// Finally write out error messages now that Log4j is closer to being stable
			for (String msg : errMsgs) {
				errorHandler.error(msg);
			}
		}
		catch(IOException e) {
			errorHandler.error("setFile("+fileName+", false) call failed.");
		}

		...
	}