Drop Apple bitmap tables when subsetting a font

CHANGELOG.md

@@ -21,6 +21,7 @@ This can also be enabled programmatically with `warnings.simplefilter('default',
 * Chinese translation of the [Tuto 7 - Creating PDF/A Documents](https://py-pdf.github.io/fpdf2/Tutorial-zh.html#-pdfa) tutorial section - _cf._ [issue #267](https://github.com/py-pdf/fpdf2/issues/267) - _cf._ [PR #2138](https://github.com/py-pdf/fpdf2/pull/2138) - thanks to @zheng-guannan577*
 * `FPDF.write_html()` makes the `id` of an element, and the `name` of an `<a>`, a named destination, so that `<a href="#...">` links within the document work, like in browsers, instead of raising `FPDFException: Named destination ... was referenced but never set` - thanks to @RavSinghChandan
 ### Fixed
+* `FPDF.output()` no longer fails with `struct.error: unpack requires a buffer of 2 bytes` for a font with Apple bitmap tables, such as the `Geneva.ttf` and `Cochin.ttc` of macOS: their `bdat` and `bloc` tables are now dropped when subsetting, like the `EBDT` and `EBLC` tables they correspond to - thanks to @RavSinghChandan
 * the generic font families of CSS Fonts 4, `system-ui`, `ui-sans-serif`, `ui-rounded`, `ui-serif` and `ui-monospace`, are now rendered with the matching core font in SVG text and `FPDF.write_html()`, as in the `og.svg` images of react-window, instead of failing with `KeyError: No suitable font for family='system-ui'` - thanks to @RavSinghChandan
 * SVG: a root `<svg>` with `width="auto"` or `height="auto"`, as Figma writes it, for instance in the country flags of the ProtonVPN apps, is now sized as if it had no `width` or `height`, from its `viewBox`, instead of failing with `ValueError: Unable to parse 'auto' as a length` - thanks to @RavSinghChandan
 * SVG: `hsl()` and `hsla()` colors are now read, with commas or space-separated, with a hue that may have an angle unit (`deg`, `grad`, `rad`, `turn`) and an alpha, as Mermaid diagrams and many stylesheets write them, instead of failing with `ValueError: unsupported color specification` - thanks to @RavSinghChandan

fpdf/output.py

@@ -1401,6 +1401,8 @@ def _add_fonts(
                     "EBDT",  # Embedded Bitmap Data Table
                     "EBLC",  # Embedded Bitmap Location Table
                     "EBSC",  # Embedded Bitmap Scaling Table
+                    "bdat",  # Apple's Bitmap Data table, the EBDT of Apple fonts
+                    "bloc",  # Apple's Bitmap Location table, the EBLC of Apple fonts
                     "SVG ",  # SVG table
                     "CPAL",  # Color Palette table
                     "COLR",  # Color table

test/fonts/test_add_font.py

@@ -5,7 +5,8 @@
 import pytest
 
 from fpdf import FPDF
-from fontTools.ttLib import TTCollection, woff2
+from fontTools.ttLib import TTCollection, TTFont, woff2
+from fontTools.ttLib.tables.DefaultTable import DefaultTable
 from test.conftest import LOREM_IPSUM, assert_pdf_equal, assert_same_file
 
 HERE = Path(__file__).resolve().parent
@@ -166,6 +167,22 @@ def test_add_font_missing_notdef_glyph(caplog):
     ) in caplog.text
 
 
+def test_add_font_with_apple_bitmap_tables(tmp_path):
+    # Like the Geneva.ttf of macOS, whose 'bloc' table fontTools cannot read:
+    # bitmap glyphs are not used in a PDF, so they are dropped like EBLC and EBDT
+    font = TTFont(HERE / "DejaVuSans.ttf")
+    for tag in ("bloc", "bdat"):
+        font[tag] = DefaultTable(tag)
+        font[tag].data = b"\x00\x02\x00\x00\x00\x00\x00\x01" + b"\xff" * 8
+    font.save(tmp_path / "DejaVuSans-bitmaps.ttf")
+    pdf = FPDF()
+    pdf.add_page()
+    pdf.add_font(family="DejaVu", fname=tmp_path / "DejaVuSans-bitmaps.ttf")
+    pdf.set_font("DejaVu", size=12)
+    pdf.cell(text="Hello world")
+    pdf.output()
+
+
 def test_font_missing_glyphs(caplog):
     pdf = FPDF()
     pdf.add_page()