[bug-gnu-libiconv] several avoidable compiler warnings when compiling libiconv

[Uwe Stöhr]

Dear libiconv team,

I am a developer of the OpenSource program LyX (www.lyx.org).
I manage the Windows builds and while compiling libiconv 1.14 using 
MSVC2015 I encountered several compiler warnings. Here are the ones for 
which I think they should be fixed:

- signed/unsigned mismatch
- inconsistent dll linkage
- different 'const' qualifiers

Here is the full list of the warnings to be fixed:

  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\utf7.h(162): warning 
C4018: '<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\utf7.h(331): warning 
C4018: '<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\hz.h(39): warning C4018: 
'<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\hz.h(51): warning C4018: 
'<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\hz.h(57): warning C4018: 
'<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\hz.h(65): warning C4018: 
'<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\hz.h(80): warning C4018: 
'<': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(47): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(91): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(142): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(258): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(418): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(422): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(503): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_unicode.h(519): 
warning C4018: '<=': signed/unsigned mismatch (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
  d:\lyxgit\2.3.x\3rdparty\libiconv\1.14\lib\loop_wchar.h(40): warning 
C4273: 'mbrtowc': inconsistent dll linkage (compiling source file 
D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c) 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]
 D:\LyXGit\2.3.x\3rdparty\libiconv\1.14\lib\iconv.c(427): warning 
C4090: 'function': different 'const' qualifiers 
[D:\LyXGit\2.3.x\compile-2015\3rdparty\libiconv\iconv.vcxproj]

thanks and regards
Uwe