fcl-base/dbase:

* fix foxpro (tablelevel 25) files so they are readable by visual foxpro
+ added file specification links for FoxPro 2.x
+ added file specification links for Visual FoxPro 9 specific changes

git-svn-id: trunk@24204 -

packages/fcl-db/src/dbase/dbf.pas

@@ -567,7 +567,7 @@ var
 begin
   if FDirty then
   begin
-    Size := Position; // Strange but it leave tailing trash bytes if I do not write that.
+    Size := Position; // Strange but it leaves tailing trash bytes if I do not write that.
     Dbf := TDbf(FBlobField.DataSet);
     Translate(true);
     Dbf.FDbfFile.MemoFile.WriteMemo(FMemoRecNo, FReadSize, Self);
@@ -1361,7 +1361,7 @@ begin
   // store recno we are editing
   FEditingRecNo := FCursor.PhysicalRecNo;
   // reread blobs, execute cancel -> clears remembered memo pageno,
-  // causing it to reread the memo contents
+  // causing it to reread the x contents
   for I := 0 to Pred(FieldDefs.Count) do
     if Assigned(FBlobStreams^[I]) then
       FBlobStreams^[I].Cancel;

packages/fcl-db/src/dbase/dbf_dbffile.pas

@@ -98,7 +98,7 @@ type
     procedure RepageIndex(AIndexFile: string);
     procedure CompactIndex(AIndexFile: string);
     function  Insert(Buffer: TRecordBuffer): integer;
-    // Write relevant dbf head as well as EOF marker at end of file if necessary
+    // Write relevant dbf header as well as EOF marker at end of file if necessary
     procedure WriteHeader; override;
     procedure ApplyAutoIncToBuffer(DestBuf: TRecordBuffer);     // dBase7 support. Writeback last next-autoinc value
     procedure FastPackTable;
@@ -352,19 +352,19 @@ var
     // (including the correction at the bottom):
     // http://msdn.microsoft.com/en-US/library/st4a0s68%28v=vs.80%29.aspx
     case version of
-      $30, $31, $32: FDbfVersion:=xVisualFoxPro;
+      $30, $31, $32 {VFP9 with new data types}: FDbfVersion:=xVisualFoxPro;
       $F5, $FB: FDbfVersion:=xFoxPro;
     end;
     if FDbfVersion = xUnknown then
       case (version and $07) of
-        $03:
+        $03: //dbf without memo. Could be foxpro, too
           if LanguageID = 0 then
             FDbfVersion := xBaseIII
           else
             FDbfVersion := xBaseIV;
         $04:
           FDbfVersion := xBaseVII;
-        $02, $05:
+        $02 {FoxBase, not readable by current Visual FoxPro driver}, $05:
           FDbfVersion := xFoxPro;
       else
         begin
@@ -631,9 +631,10 @@ begin
       // Note: VerDBF may be changed later on depending on what features/fields are used
       // (autoincrement etc)
       case FDbfVersion of
-        xFoxPro: PDbfHdr(Header)^.VerDBF := $02; {FoxBASE}
+        xFoxPro: PDbfHdr(Header)^.VerDBF := $03; {FoxBASE+/FoxPro/dBASE III PLUS/dBASE IV, no memo
+        alternative $02 FoxBASE is not readable by current Visual FoxPro drivers}
         xVisualFoxPro: PDbfHdr(Header)^.VerDBF := $30; {Visual FoxPro no autoincrement,no varchar}
-        else PDbfHdr(Header)^.VerDBF := $03; {FoxBASE+/dBASE III PLUS, no memo!?}
+        else PDbfHdr(Header)^.VerDBF := $03; {FoxBASE+/FoxPro/dBASE III PLUS/dBASE IV, no memo}
       end;
       // standard language WE/Western Europe, dBase III no language support
       if FDbfVersion = xBaseIII then
@@ -699,7 +700,10 @@ begin
         if (FDbfVersion in [xFoxPro,xVisualFoxPro]) then
           lFieldDescIII.FieldOffset := SwapIntLE(lFieldOffset);
         // Adjust the version info if needed for supporting field types used:
-        if (PDbfHdr(Header)^.VerDBF = $02) and (lFieldDef.NativeFieldType in ['0', 'Y', 'T', 'O', '+']) then
+        // VerDBF=$03 also includes dbase formats, so we perform an extra check
+        if (FDBFVersion in [xUnknown,xFoxPro,xVisualFoxPro]) and
+          (PDbfHdr(Header)^.VerDBF in [$02,$03]) and
+          (lFieldDef.NativeFieldType in ['0', 'Y', 'T', 'O', '+']) then
           PDbfHdr(Header)^.VerDBF := $30; {Visual FoxPro}
         if (PDbfHdr(Header)^.VerDBF = $30) and (lFieldDef.NativeFieldType = '+') then
           PDbfHdr(Header)^.VerDBF := $31; {Visual FoxPro, autoincrement enabled}
@@ -727,7 +731,7 @@ begin
     begin
       case FDbfVersion of
         xBaseIII: PDbfHdr(Header)^.VerDBF := PDbfHdr(Header)^.VerDBF or $80;
-        xFoxPro: if PDbfHdr(Header)^.VerDBF = $02 then {change from FoxBASE to...}
+        xFoxPro: if (PDbfHdr(Header)^.VerDBF in [$02,$03]) then {change from FoxBASE to...}
           PDbfHdr(Header)^.VerDBF := $F5; {...FoxPro 2.x (or earlier) with memo}
         xVisualFoxPro: //MSDN says field 28 or $02 to set memo flag
           PDbfHdr(Header)^.MDXFlag := PDbfHdr(Header)^.MDXFlag or $02;
@@ -1773,6 +1777,7 @@ begin
   Dst := PChar(Dst) + TempFieldDef.Offset;
   asciiContents := false;
   // todo: check/add visualfoxpro autoincrement capability, null values, DateTime, Currency, and Double data types
+  // see comments in dbf_fields for details
   case TempFieldDef.NativeFieldType of
     '+', 'I' {autoincrement, integer}:
       begin

packages/fcl-db/src/dbase/dbf_fields.pas

@@ -568,9 +568,25 @@ begin
     No check, includes:
     http://msdn.microsoft.com/en-US/library/ww305zh2%28v=vs.80%29.aspx
     P Picture (in at least Visual FoxPro)
-    V Varchar/varchar binary (in at least Visual FoxPro) 1 byte up to 255 bytes (or perhaps 254)
-    W Blob (in at least Visual FoxPro), 4 bytes in a table; stored in .fpt
-    Q Varbinary (in at least Visual Foxpro)
+    V Varchar/varchar binary (in Visual FoxPro 9) 1 byte up to 254 bytes.
+      Same storage as char (padded spaces) but padding is removed on display
+      http://foxcentral.net/microsoft/WhatsNewInVFP9_Chapter09.htm
+    W Blob (Visual FoxPro 9), 4 bytes in a table; stored in .fpt
+      http://foxcentral.net/microsoft/WhatsNewInVFP9_Chapter09.htm
+    Q Varchar (binary) (in Visual Foxpro 9):
+      accepts null, up to 254 characters (stored as padded with spaces), no code page translations
+      note varchar (binary)<>varbinary
+      http://foxcentral.net/microsoft/WhatsNewInVFP9_Chapter09.htm
+    Varchar/varbinary storage:
+      Uses _NullFlags:
+      bit n=1: nullable field number n is null (as in previous versions)
+      bit n=0: varchar/varbinary field is full/fills space
+      bit n=1: varchar/varbinary is not full; last byte of field data contains size
+      If varchar/varbinary field AND nullable field, 2 bits are used:
+      - lower bit=full status
+      - higher bit=null status
+
+
     }
   end; // case
 end;

packages/fcl-db/src/dbase/dbf_lang.pas

@@ -85,7 +85,7 @@ const
   FoxLangId_Iceland_861   = $67; // DOS
   FoxLangId_Czech_895     = $68; // DOS Kamenicky
 // ...
-  DbfLangId_POL_620       = $69; // DOS Mazovia
+  DbfLangId_POL_620       = $69; // DOS Polish Mazovia
 // ...
   FoxLangId_Greek_737     = $6A; // DOS (437G)
   FoxLangId_Turkish_857   = $6B; // DOS
@@ -123,7 +123,7 @@ const
   DbfLocale_Bul868     = $020000;
 
 //*************************************************************************//
-// DB3/DB4/FoxPro/Visual Foxpro Language ID to CodePage convert table
+// DB3/DB4/FoxPro/Visual Foxpro Language ID to CodePage conversion table
 // Visual FoxPro docs call language ID "code page mark"
 // or "code page identifier"
 //*************************************************************************//

packages/fcl-db/src/dbase/dbf_pgfile.pas

@@ -560,7 +560,7 @@ begin
   begin
     // get size left in file for header
     size := FStream.Size - FHeaderOffset;
-    // header start before EOF?
+    // does header start before EOF?
     if size >= 0 then
     begin
       // go to header start
@@ -576,7 +576,7 @@ begin
         Read(FHeader, size);
       end;
     end else begin
-      // header start before EOF, clear header
+      // clear header
       size := 0;
     end;
     FillChar(FHeader[size], FHeaderSize-size, 0);

packages/fcl-db/src/dbase/readme.txt

@@ -27,5 +27,11 @@ http://msdn.microsoft.com/en-US/library/st4a0s68%28v=vs.80%29.aspx
 note however that the file type/magic number at offset 0 is incorrect.
 A community member amended these. See bottom of page
 
+Visual FoxPro 9 specific changes:
+http://foxcentral.net/microsoft/WhatsNewInVFP9_Chapter09.htm
+
+FoxPro 2.x:
+http://support.microsoft.com/kb/98743/en-us
+
+Flagship/FoxPro/Clipper/DBase III..V .dbf file format description
 ftp://fship.com/pub/multisoft/flagship/docu/dbfspecs.txt
-Flagship/FoxPro/Clipper/DBase III..V .dbf file format description