OK, I've almost got a wine-gecko package built 100% from source, but there's a problem: the gcc version in Debian's mingw32, namely gcc 4.2.1-sjlj, apparently miscompiles the wine-gecko 1.0.0 sources, the resulting Gecko just crashes. (The mingw32 version in oldstable, 3.4.5 something, compiles it correctly, but I can't reasonably build-depend on it, as that version is not even in the current stable.)
(Note that this 4.2.1-sjlj might not suffer from that gcc bug 9381 mentioned on the wiki, as the testcases for it doesn't seem to crash. Or aren't they supposed to crash?)
I also seem to recall the gcc 4.4-based mingw32 compiler, available in unstable, also refusing to compile those sources at all, due to numerous problems with the headers, such as inconsistently declared calling conventions for methods and stuff.
I'm not sure what to do about this. Any ideas about something I can do to make it build with gcc 4.2 or 4.4?
I can also mention that I managed to build this package completely without wintools.zip at all, by simply patching out the build of the cross-compiled xpidl.exe. It's an xpcom developer tool and probably not needed at runtime (and the xpidl.exe in the official wine-gecko cab would probably have failed to run anyway, because its dll dependencies aren't included in the cab file). A host build of xpidl is still needed to build Gecko, but for that, only the regular Linux version of glib and libIDL is needed, not wintools. You can disable cross-compiling xpidl.exe by editing xpcom/typelib/xpidl/Makefile.in and kill the two lines commented with "Sadly, the code here is too smart for the WinCE/Symbian compiler's brain".