From 039b6fcc5bc8d91ad709512a891ea65d60588124 Mon Sep 17 00:00:00 2001
From: Jens Kraemer <jk@jkraemer.net>
Date: Thu, 6 Nov 2025 09:40:45 +0800
Subject: [PATCH] fixes rendering of images with a percentage as width or
 height

Images with style='width: X%' were not being rendered in writeHTMLCell because
the percentage was calculated against a reference size of 1 unit instead of the
available content width. This resulted in images being ~0.3 units wide
(essentially invisible).
---
 lib/rbpdf.rb                |  9 ++++--
 test/rbpdf_htmlcell_test.rb | 64 +++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/lib/rbpdf.rb b/lib/rbpdf.rb
index 62d312c3..91c84cd1 100755
--- a/lib/rbpdf.rb
+++ b/lib/rbpdf.rb
@@ -14805,11 +14805,16 @@ def openHTMLTagHandler(dom, key, cell)
         end
         iw = 0
         if tag['width']
-          iw = getHTMLUnitToUnits(tag['width'], 1, 'px', false)
+          # Calculate available width for percentage-based widths
+          available_width = @rtl ? (@x - @l_margin) : (@w - @r_margin - @x)
+          available_width -= 2 * @c_margin if available_width > 0
+          iw = getHTMLUnitToUnits(tag['width'], available_width, 'px', false)
         end
         ih = 0
         if tag['height']
-          ih = getHTMLUnitToUnits(tag['height'], 1, 'px', false)
+          # Use page height for percentage-based heights
+          available_height = @h - @t_margin - @b_margin
+          ih = getHTMLUnitToUnits(tag['height'], available_height, 'px', false)
         end
 
         # store original margin values
diff --git a/test/rbpdf_htmlcell_test.rb b/test/rbpdf_htmlcell_test.rb
index 39f232ff..3625dc7b 100644
--- a/test/rbpdf_htmlcell_test.rb
+++ b/test/rbpdf_htmlcell_test.rb
@@ -77,4 +77,68 @@ class RbpdfTest < Test::Unit::TestCase
     no = pdf.get_num_pages
     assert_equal 1, no
   end
+
+  test "write_html_cell with image percentage width" do
+    # Test that images with percentage-based width styles are actually embedded
+    pdf = RBPDF.new
+    pdf.add_page()
+
+    # Test image path - using the logo_example.png from the repo
+    img_path = File.join(File.dirname(__FILE__), '..', 'logo_example.png')
+
+    # Create PDF with image using percentage width
+    html_with_percentage = "<p>Image with percentage width:</p><img src='#{img_path}' style='width: 30%'>"
+    pdf.write_html_cell(0, 0, '', '', html_with_percentage)
+
+    # Check if the image was embedded
+    images = pdf.instance_variable_get('@images')
+    assert_equal 1, images.length, "Expected 1 image to be embedded in cache"
+
+    # More importantly, check that the PDF actually contains image data
+    # by verifying the PDF size is much larger than an empty PDF
+    output = pdf.output('', 'S')
+
+    # Create a reference PDF without any image
+    pdf_no_img = RBPDF.new
+    pdf_no_img.add_page()
+    pdf_no_img.write_html_cell(0, 0, '', '', '<p>Image with percentage width:</p>')
+    output_no_img = pdf_no_img.output('', 'S')
+
+    # PDF with image should be significantly larger (image data embedded)
+    assert output.length > output_no_img.length + 10000,
+      "Expected PDF with image (#{output.length} bytes) to be much larger than PDF without image (#{output_no_img.length} bytes). Image may not have been embedded."
+  end
+
+  test "write_html_cell with image percentage width generates output" do
+    pdf = RBPDF.new
+    pdf.add_page()
+
+    img_path = File.join(File.dirname(__FILE__), '..', 'logo_example.png')
+
+    # Test both plain and percentage width styles
+    html = <<-HTML
+      <h3>Test: Image rendering with percentage width</h3>
+      <p>Image without style (should work):</p>
+      <img src='#{img_path}'>
+      <p>Image with width=50 attribute (should work):</p>
+      <img src='#{img_path}' width='50'>
+      <p>Image with style width percentage (should work):</p>
+      <img src='#{img_path}' style='width: 30%'>
+      <p>Image with style width pixels (should work):</p>
+      <img src='#{img_path}' style='width: 50px'>
+    HTML
+
+    pdf.write_html_cell(0, 0, '', '', html)
+
+    # Generate PDF output to verify it doesn't crash
+    output = pdf.output('', 'S')
+    assert_not_nil output
+    assert output.length > 0
+
+    # Optionally write to file for manual inspection
+    if ENV['OUTPUT']
+      File.write('test_image_percentage_width.pdf', output)
+      puts "Generated test_image_percentage_width.pdf for manual inspection"
+    end
+  end
 end