Split emphasis markers at paragraph breaks, merge heading lines

lib/reverse_markdown/converters/base.rb

@@ -15,6 +15,26 @@ def escape_keychars(string)
         string.gsub(/(?<!\\)[*_]/, '*' => '\*', '_' => '\_')
       end
 
+      # Wrap content with markers (e.g., ** or _), splitting at paragraph breaks
+      # so markers don't span across breaks (which breaks markdown rendering)
+      def wrap_with_markers(content, marker)
+        # Split on paragraph breaks, preserving the breaks
+        segments = content.split(/(\s*\n\s*\n\s*)/)
+
+        segments.map.with_index do |segment, i|
+          if i.odd?  # This is a break segment (captured delimiter)
+            segment
+          elsif segment.strip.empty?
+            segment
+          else
+            # Wrap with markers, preserving border whitespace
+            leading = segment[/\A\s*/]
+            trailing = segment[/\s*\z/]
+            "#{leading}#{marker}#{segment.strip}#{marker}#{trailing}"
+          end
+        end.join
+      end
+
       def extract_title(node)
         title = escape_keychars(node['title'].to_s)
         title.empty? ? '' : %[ "#{title}"]

lib/reverse_markdown/converters/em.rb

@@ -6,7 +6,7 @@ def convert(node, state = {})
         if content.strip.empty? || state[:already_italic]
           content
         else
-          "#{content[/^\s*/]}_#{content.strip}_#{content[/\s*$/]}"
+          wrap_with_markers(content, '_')
         end
       end
     end

lib/reverse_markdown/converters/h.rb

@@ -3,7 +3,10 @@ module Converters
     class H < Base
       def convert(node, state = {})
         prefix = '#' * node.name[/\d/].to_i
-        ["\n", prefix, ' ', treat_children(node, state), "\n"].join
+        content = treat_children(node, state).strip
+        # Merge lines into one (markdown headings can't span multiple lines)
+        content = content.split(/\s*\n\s*/).join(' ')
+        "\n#{prefix} #{content}\n"
       end
     end
 

lib/reverse_markdown/converters/strong.rb

@@ -6,7 +6,7 @@ def convert(node, state = {})
         if content.strip.empty? || state[:already_strong]
           content
         else
-          "#{content[/^\s*/]}**#{content.strip}**#{content[/\s*$/]}"
+          wrap_with_markers(content, '**')
         end
       end
     end

spec/lib/reverse_markdown/converters/em_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe ReverseMarkdown::Converters::Em do
+  let(:converter) { ReverseMarkdown::Converters::Em.new }
+
+  it 'returns an empty string if the node is empty' do
+    input = node_for('<em></em>')
+    expect(converter.convert(input)).to eq ''
+  end
+
+  it 'returns just the content if the em tag is nested in another em' do
+    input = node_for('<em><em>foo</em></em>')
+    expect(converter.convert(input.children.first, already_italic: true)).to eq 'foo'
+  end
+
+  it 'moves border whitespaces outside of the delimiters tag' do
+    input = node_for("<em> \n foo </em>")
+    expect(converter.convert(input)).to eq " _foo_ "
+  end
+
+  it 'splits markers at paragraph breaks' do
+    # Issue #95: <br><br> inside em creates a paragraph break
+    # Markers must be split so markdown renders correctly
+    result = ReverseMarkdown.convert('<em>hello<br><br>world</em>')
+    expect(result).to include('_hello_')
+    expect(result).to include('_world_')
+  end
+end

spec/lib/reverse_markdown/converters/h_spec.rb

@@ -0,0 +1,16 @@
+require 'spec_helper'
+
+describe ReverseMarkdown::Converters::H do
+  let(:converter) { ReverseMarkdown::Converters::H.new }
+
+  it 'merges line breaks into single line' do
+    # Markdown headings can't span multiple lines, so merge them
+    result = ReverseMarkdown.convert('<h1>foo<br>bar</h1>')
+    expect(result.strip).to eq '# foo bar'
+  end
+
+  it 'handles multiple line breaks' do
+    result = ReverseMarkdown.convert('<h2>a<br>b<br>c</h2>')
+    expect(result.strip).to eq '## a b c'
+  end
+end

spec/lib/reverse_markdown/converters/strong_spec.rb

@@ -17,4 +17,12 @@
     input = node_for("<strong> \n foo </strong>")
     expect(converter.convert(input)).to eq " **foo** "
   end
+
+  it 'splits markers at paragraph breaks' do
+    # Issue #95: <br><br> inside strong creates a paragraph break
+    # Markers must be split so markdown renders correctly
+    result = ReverseMarkdown.convert('<strong>hello<br><br>world</strong>')
+    expect(result).to include('**hello**')
+    expect(result).to include('**world**')
+  end
 end