Convert pin names to new overbar format

Fixes bug 6 of https://gitlab.com/kicad/code/kicad/issues/8591, thereby
closing the issue:

Fixes https://gitlab.com/kicad/code/kicad/issues/8591

eeschema/sch_file_versions.h

@@ -36,9 +36,10 @@
 
 //#define SEXPR_SYMBOL_LIB_FILE_VERSION  20200820
 
-//#define SEXPR_SYMBOL_LIB_FILE_VERSION  20200827  // Remove host tag
+//#define SEXPR_SYMBOL_LIB_FILE_VERSION  20200827  // Remove host tag.
 //#define SEXPR_SYMBOL_LIB_FILE_VERSION  20200908  // Add include in BOM and on board support.
-#define SEXPR_SYMBOL_LIB_FILE_VERSION  20201005    // Separate ki_fp_filters by spaces
+//#define SEXPR_SYMBOL_LIB_FILE_VERSION  20201005  // Separate ki_fp_filters by spaces.
+#define SEXPR_SYMBOL_LIB_FILE_VERSION 20210619   // Change pin overbar syntax from `~...~` to `~{...}`.
 
 
 /**
@@ -54,7 +55,7 @@
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20200618  // Disallow duplicate field ids.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20200714  // Add alternate pin definitions.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20200820
-//#define SEXPR_SCHEMATIC_FILE_VERSION 20200827  // Remove host tag
+//#define SEXPR_SCHEMATIC_FILE_VERSION 20200827  // Remove host tag.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20200828  // Add footprint to symbol_instances.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20201015  // Add sheet instance properties.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20210123  // Rename "unconnected" pintype to "no_connect".
@@ -62,4 +63,4 @@
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20210126  // Fix bug with writing pin uuids.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20210406  // Add schematic level uuids.
 //#define SEXPR_SCHEMATIC_FILE_VERSION 20210606  // Change overbar syntax from `~...~` to `~{...}`.
-#define SEXPR_SCHEMATIC_FILE_VERSION 20210615  // Update overbar syntax in net names
+#define SEXPR_SCHEMATIC_FILE_VERSION 20210615  // Update overbar syntax in net names.

eeschema/sch_plugins/kicad/sch_sexpr_parser.cpp

@@ -1286,7 +1286,11 @@ LIB_PIN* SCH_SEXPR_PARSER::parsePin()
                 THROW_IO_ERROR( error );
             }
 
-            pin->SetName( FromUTF8() );
+            if( m_requiredVersion < 20210606 )
+                pin->SetName( ConvertToNewOverbarNotation( FromUTF8() ) );
+            else
+                pin->SetName( FromUTF8() );
+
             token = NextTok();
 
             if( token != T_RIGHT )