Description Kshitiz Bhattarai 2020-12-02 13:09:02 EST

The original fix https://github.com/eclipse/rt.equinox.bundles/commit/9a0d95dd4a5d08977564f4ca5930b5570bccdc8d to this bug https://bugs.eclipse.org/bugs/show_bug.cgi?id=562843 is not valid. 

It does invalid logic to decode path parameter and if the path parameter contains / as encoded %2F ex:

/view/%2FTABLES%2FTMP%2FZREST_SBOOK/data

Would result in,

Error 500 java.lang.IllegalArgumentException: URLDecoder: Incomplete trailing escape (%) pattern.

This is essentially due to the fact that the logic to substring uses the decoded path parameter rather than original request URI.

ex: 
In the code:
```
			if (pos > -1) {
				String newServletPath = requestURI.substring(0, pos);
				pathInfo = decode(requestURI.substring(pos));
				servletPath = decode(newServletPath);
				pos = servletPath.lastIndexOf('/');

				continue;
			}
```

If first call say our requestURI is following,

/view/%2FTABLES%2FTMP%2FZREST_SBOOK/data

Then newServletPath uses requestURI which isn't decoded.

And now we get, 
servletPath = /view//TABLES/TMP/ZREST_SBOOK 
pathInfo = /data

However when we do servletPath.lastIndexOf it now uses decoded string and get / which results into position being wrong and we will now do for

newServletPath = /view/%2FTABLES%2

This will result on URLDecoder error.

One option to fix this issue could be:

```
         String newServletPath = requestURI.substring(0, pos);
         pathInfo = decode(requestURI.substring(pos));
         requestURI = newServletPath; <- Use requestURI for processing and don't decode servlet path.
```