change UTF8& operator+=( wchar_t ch ) to UTF8& operator+=( unsigned ch ), because swig does not like wchar_t.

(on Linux, wchar_t is a unsigned int, on Windows a unsigned short, so always using a unsigned int do not create issues)

common/text_utils.cpp

@@ -45,8 +45,8 @@ std::pair<UTF8, std::vector<bool>> ProcessOverbars( const UTF8& aText )
         }
 
         // remember: *chIt is not necessary a ASCII7 char.
-        // it is an unsigned ( wchar_t ) giving a multibyte char in UTF8 strings
-        text += wchar_t( *chIt );
+        // it is an unsigned giving a multibyte char in UTF8 strings
+        text += *chIt;
 
         flags.push_back( overbar );
     }

common/utf8.cpp

@@ -218,15 +218,15 @@ UTF8::UTF8( const wchar_t* txt ) :
 }
 
 
-UTF8& UTF8::operator+=( wchar_t ch )
+UTF8& UTF8::operator+=( unsigned w_ch )
 {
-    if( ch <= 0x7F )
-        m_s.operator+=( char( ch ) );
+    if( w_ch <= 0x7F )
+        m_s.operator+=( char( w_ch ) );
     else
     {
-        wchar_t wide_chr[2];    // buffer to store wide chars (unicode) read from aText
+        wchar_t wide_chr[2];    // buffer to store wide chars (UTF16) read from aText
         wide_chr[1] = 0;
-        wide_chr[0] = ch;
+        wide_chr[0] = w_ch;
         UTF8 substr( wide_chr );
         m_s += substr.m_s;
     }

eeschema/component_references_lister.cpp

@@ -709,7 +709,7 @@ SCH_REFERENCE::SCH_REFERENCE( SCH_COMPONENT* aComponent, LIB_PART* aLibPart,
 void SCH_REFERENCE::Annotate()
 {
     if( m_NumRef < 0 )
-        m_Ref += wxChar( '?' );
+        m_Ref += '?';
     else
     {
         // To avoid a risk of duplicate, for power components

include/utf8.h

@@ -146,8 +146,9 @@ public:
     }
 
     /// Append a wide (unicode) char to the UTF8 string.
-    /// if this char is not a ASCII7 char, it will be added as a UTF8 multibyte seqence
-    UTF8& operator+=( wchar_t ch );
+    /// if this wide char is not a ASCII7 char, it will be added as a UTF8 multibyte seqence
+    /// @param w_ch is a UTF-16 value (can be a UTF-32 on Linux)
+    UTF8& operator+=( unsigned w_ch );
 
     // std::string::npos is not constexpr, so we can't use it in an
     // initializer.