From be62c011961bc3d2dfb981cbf7cebdd4a7e43e01 Mon Sep 17 00:00:00 2001
From: Joel Linn <jl@conductive.de>
Date: Thu, 14 Jan 2021 11:57:08 +0100
Subject: [PATCH] fcl-pdf: fix for monospace fonts. fixes #38354

---
 packages/fcl-pdf/src/fpparsettf.pp | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/packages/fcl-pdf/src/fpparsettf.pp b/packages/fcl-pdf/src/fpparsettf.pp
index fc7c243b5c..9dc055fca4 100644
--- a/packages/fcl-pdf/src/fpparsettf.pp
+++ b/packages/fcl-pdf/src/fpparsettf.pp
@@ -822,13 +822,13 @@ begin
   if embed and not Embeddable then
     raise ETTF.Create(rsFontEmbeddingNotAllowed);
   PrepareEncoding(Encoding);
-//  MissingWidth:=ToNatural(Widths[Chars[CharCodes^[32]]].AdvanceWidth);  // Char(32) - Space character
-  FMissingWidth := Widths[Chars[CharCodes^[32]]].AdvanceWidth;  // Char(32) - Space character
+//  MissingWidth:=ToNatural(GetAdvanceWidth(Chars[CharCodes^[32]]));  // Char(32) - Space character
+  FMissingWidth := GetAdvanceWidth(Chars[CharCodes^[32]]);  // Char(32) - Space character
   for I:=0 to 255 do
   begin
     if (CharCodes^[i]>=0) and (CharCodes^[i]<=High(Chars))
-    and (Widths[Chars[CharCodes^[i]]].AdvanceWidth> 0) and (CharNames^[i]<> '.notdef') then
-      CharWidth[I]:= ToNatural(Widths[Chars[CharCodes^[I]]].AdvanceWidth)
+    and (GetAdvanceWidth(Chars[CharCodes^[i]])> 0) and (CharNames^[i]<> '.notdef') then
+      CharWidth[I]:= ToNatural(GetAdvanceWidth(Chars[CharCodes^[I]]))
     else
       CharWidth[I]:= FMissingWidth;
   end;
@@ -930,8 +930,19 @@ begin
 end;
 
 function TTFFileInfo.GetAdvanceWidth(AIndex: word): word;
-begin
-  Result := Widths[AIndex].AdvanceWidth;
+var
+  i: SizeInt;
+begin
+  // There may be more glyphs than elements in the array, in which
+  // case the last entry is to be used.
+  // https://docs.microsoft.com/en-us/typography/opentype/spec/hmtx
+  i := Length(Widths);
+  if AIndex >= i then
+    Dec(i)
+  else
+    i := AIndex;
+
+  Result := Widths[i].AdvanceWidth;
 end;
 
 function TTFFileInfo.ItalicAngle: single;
@@ -972,7 +983,7 @@ function TTFFileInfo.GetMissingWidth: integer;
 begin
   if FMissingWidth = 0 then
   begin
-    FMissingWidth := Widths[Chars[CharCodes^[32]]].AdvanceWidth;  // 32 is in reference to the Space character
+    FMissingWidth := GetAdvanceWidth(Chars[CharCodes^[32]]);  // 32 is in reference to the Space character
   end;
   Result := FMissingWidth;
 end;
-- 
2.27.0