[easytag] Add checks for extra id3lib declarations

[David King <davidk src gnome org>]

commit 54ba8cf11c92650ab20d33670df66144c6ee2e67
Author: David King <amigadave amigadave com>
Date:   Fri Feb 6 20:43:33 2015 +0000

    Add checks for extra id3lib declarations
    
    Fix compilation of id3lib wrapper on Debian, which includes some C
    wrapper functions which were not in the id3lib 3.8.3 release, by
    checking for the declarations with AC_CHECK_DECLS.

 configure.ac                 |    7 ++++++-
 src/tags/id3lib/id3_bugfix.h |   20 +++++++++++++-------
 2 files changed, 19 insertions(+), 8 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 82463e1..146a42b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -277,7 +277,12 @@ AS_IF([test "x$have_mp3" = "xyes" -a "x$enable_id3v23" != "xno"],
 
        AC_SUBST([ID3LIB_LIBS], [$ac_cv_search_ID3Tag_Link])
        AC_DEFINE([ENABLE_ID3LIB], [], [Define for ID3v2.3 support])
-       ID3LIB_VERSION="(id3lib-$ID3LIB_MAJOR.$ID3LIB_MINOR.$ID3LIB_PATCH)"],
+       ID3LIB_VERSION="(id3lib-$ID3LIB_MAJOR.$ID3LIB_MINOR.$ID3LIB_PATCH)"
+       AC_CHECK_DECLS([ID3Field_SetEncoding,
+                       ID3Field_GetEncoding,
+                       ID3Field_IsEncodable],
+                       [], [],
+                      [[#include <id3.h>]])],
       [have_id3lib=no])
 
 
diff --git a/src/tags/id3lib/id3_bugfix.h b/src/tags/id3lib/id3_bugfix.h
index f21f9ed..5eb39cf 100644
--- a/src/tags/id3lib/id3_bugfix.h
+++ b/src/tags/id3lib/id3_bugfix.h
@@ -28,13 +28,19 @@
 
 G_BEGIN_DECLS
 
-  ID3_C_EXPORT bool                  CCONV ID3Field_SetEncoding    (ID3Field *field, ID3_TextEnc enc);
-  ID3_C_EXPORT ID3_TextEnc           CCONV ID3Field_GetEncoding    (const ID3Field *field);
-  ID3_C_EXPORT bool                  CCONV ID3Field_IsEncodable    (const ID3Field *field);
-  ID3_C_EXPORT ID3_FieldType         CCONV ID3Field_GetType        (const ID3Field *field);
-  //ID3_C_EXPORT ID3_FieldID           CCONV ID3Field_GetID          (const ID3Field *field);
-
-  ID3_C_EXPORT const Mp3_Headerinfo* CCONV ID3Tag_GetMp3HeaderInfo (ID3Tag *tag);
+#if !HAVE_DECL_ID3FIELD_SETENCODING
+ID3_C_EXPORT bool                  CCONV ID3Field_SetEncoding    (ID3Field *field, ID3_TextEnc enc);
+#endif /* !HAVE_DECL_ID3FIELD_SETENCODING */
+#if !HAVE_DECL_ID3FIELD_GETENCODING
+ID3_C_EXPORT ID3_TextEnc           CCONV ID3Field_GetEncoding    (const ID3Field *field);
+#endif /* !HAVE_DECL_ID3FIELD_GETENCODING */
+#if !HAVE_DECL_ID3FIELD_ISENCODABLE
+ID3_C_EXPORT bool                  CCONV ID3Field_IsEncodable    (const ID3Field *field);
+#endif /* !HAVE_DECL_ID3FIELD_ISENCODABLE */
+ID3_C_EXPORT ID3_FieldType         CCONV ID3Field_GetType        (const ID3Field *field);
+//ID3_C_EXPORT ID3_FieldID           CCONV ID3Field_GetID          (const ID3Field *field);
+
+ID3_C_EXPORT const Mp3_Headerinfo* CCONV ID3Tag_GetMp3HeaderInfo (ID3Tag *tag);
   
 G_END_DECLS