otherwise, it may very hard to find what is wrong
Created attachment 15162 [details] HostConfig.java.patch a little bit more user-friendly
Created attachment 15163 [details] HostConfig.java.patch2 yet more user-friendliness (and an error less)
I don't understand: your patches actually remove logging statements, yet the title of this issue asks to add a warning, no?
Created attachment 15742 [details] HostConfig.java.patch3 corrected - now using diff -u HostConfig.java.orig HostConfig.java
Specifying a non-existing appBase is not necessarily invalid. By default, Tomcat 7 will create the appBase if it does not already exist. I have tweaked the tests Tomcat does in case a file is specified as an appBase. I do not propose back-porting this to Tomcat 5 or 6.