As of 1.4beta2_b77, javac seems to no longer compile correctly
when the Java source files are touched. (This has only been
verified on Win32, but it may occur on other platforms as well).
If the original "last modified" dates are restored, the Java
source files will again compile correctly.

This problem can be seen to occur when using 1.4beta2_b77 as the
bootstrap for building 1.4. (FYI: Licensees who are porting 1.4
were told that they are required to use b71 or later as the boot-
strap in order to fully support assertions in the 1.4 HotSpot
compiler.) The problem doesn't seem to occur in when using one
of builds b71-b76 as the bootstrap.

The attached Java application (Touch.java) can be used to recreate
the problem. It takes a ZIP file as an argument (representing a
zipped source distribution) and writes a new ZIP file: Touched.zip.
In the latter, the Java source files will have the last modified
date set to the current date. All other file types will have the
original last modified date preserved. For example:

java Touch j2re-1_4_0-beta2-src-b77-solwin-22_aug_2001.zip

The original (untouched) ZIP file will build correctly. However,
Touched.zip will encounter numerous Java compilation errors when
a build is attempted -- see attached Errors.txt file. A typically
produced error message is:

An explicit 'this' qualifier must be used to select
the desired instance.

This looks like a pretty nasty javac problem that could be encountered
outside of the build process. I have seen the "explicit this qualifier
required" error before on very simple Java applications that compiled
cleanly on JDK 1.3.