Replace fdopen by conversion to CFILE

[lucasb-eyer]

So it works with your recent commit to julia-lang :)

[timholy]

Perhaps surprisingly, I'm a little reluctant to do this. I want to keep supporting release 0.2, and as you noticed CFILE support is only in 0.3. I guess I could fork Images into separate branches, but that seems like a pain for future development and may not be worth it for such a simple change.

[lucasb-eyer]

Ah, I didn't know fdopen was in 0.2, since it's missing in the docs and a quick grep for fdopen in the 0.2 tagged sources doesn't show any result. That's actually why I pulled the newest julia and saw your issue over there.

[timholy]

Rats, it looks like I deleted the definition of fdopen I put in that file. Will fix. Thanks for letting me know!

[lucasb-eyer]

Shall I close this pull request then?

[timholy]

OK, it should be in master, would you check out and test?

[lucasb-eyer]

Yup, that works thanks. But you should use the systemerror functions for C calls which set errno on failure. You can change it now, or I can make a pull-request sometime later, as I set out to fix it through julia and the julia-libs I use.

[timholy]

Thanks for the tip! You mean just changing the last line of error(wand::MagickWand) to systemerror(msg, true)?

[lucasb-eyer]

I mean

-    if FILEp == 0
-        error("fdopen failed")
-    end
+    systemerror("fdopen failed", FILEp == 0)

and either

-    ccall(:fseek, Cint, (Ptr{Void}, Clong, Cint), 
-          FILEp, convert(Clong, offset), int32(0)) == 0 ||
-          error("fseek failed")
+    systemerror("fseek failed", ccall(:fseek, Cint, (Ptr{Void}, Clong, Cint), FILEp, convert(Clong, offset), int32(0)) == 0)

or

-    ccall(:fseek, Cint, (Ptr{Void}, Clong, Cint), 
-          FILEp, convert(Clong, offset), int32(0)) == 0 ||
-          error("fseek failed")
+    status = ccall(:fseek, Cint, (Ptr{Void}, Clong, Cint), FILEp, convert(Clong, offset), int32(0))
+    systemerror("fseek failed", status == 0)

[timholy]

Ah, right. (I had mentally moved on to your other issue.)

I'll be happy to do this, if you prefer, though obviously this was rather close to a PR already!