SharedHttpCacheStorage is not stripping * characters from URIs, even though this character is illegal on Windows

[gab1one]

Hi Tycho maintainers,
I discovered a bug in the handling of characters that are valid parts of URIs but not legal file names under Windows. Building with an update site that contains a * character in the path, causes the whole build to fail.

This is caused by the URI cleanup in SharedHttpCacheStorage not stripping * characters from URIs:

tycho/p2-maven-plugin/src/main/java/org/eclipse/tycho/p2maven/transport/SharedHttpCacheStorage.java

Lines 153 to 154 in e3e22e2

	String cleanPath = uri.normalize().toASCIIString().replace(':', '/').replace('?', '/').replace('&', '/')
	.replaceAll("/+", "/");

, then it tries to create a file with the * character in its path, resulting in a RuntimeException:

Failed to load p2 repository with ID '<ID>` from location <REPOURL_WITH_ASTERISK>: Unable to read repository at <REPOURL_WITH_ASTERISK>. Cannot create directory

Taking a look at the legal special characters in URIs: - . _ ~ : / ? # [ ] @ ! $ & ' ( ) * + , ; = and the characters that are not allowed in Windows file names: : " / \ | ? * < >, we can see that the * character is the only one character remaining in the intersection of both sets ( / ? * :) that is not yet covered by this method.

See this PR for the fix: #2590