Fix accept_table with incomplete rows (ruby#1599)

`header.zip(*body)` pads shorter rows with nil, causing NoMethodError in
column width calculation. Also fix body rendering to output the correct
number of columns for short rows instead of silently dropping them.

Author: st0012

lib/rdoc/markup/to_rdoc.rb

@@ -243,7 +243,7 @@ def accept_table(header, body, aligns)
     header = header.map { |h| attributes h }
     body = body.map { |row| row.map { |t| attributes t } }
     widths = header.zip(*body).map do |cols|
-      cols.map { |col| calculate_text_width(col) }.max
+      cols.compact.map { |col| calculate_text_width(col) }.max
     end
     aligns = aligns.map do |a|
       case a
@@ -261,7 +261,8 @@ def accept_table(header, body, aligns)
     end.join("|").rstrip << "\n"
     @res << widths.map {|w| "-" * w }.join("|") << "\n"
     body.each do |row|
-      @res << row.zip(widths, aligns).map do |t, w, a|
+      @res << widths.zip(aligns).each_with_index.map do |(w, a), i|
+        t = row[i] || ""
         extra_width = t.size - calculate_text_width(t)
         t.__send__(a, w + extra_width)
       end.join("|").rstrip << "\n"

test/rdoc/markup/to_ansi_test.rb

@@ -348,6 +348,16 @@ def list_verbatim
     assert_equal expected, @to.end_accepting
   end
 
+  def accept_table_ragged_rows
+    expected = "\e[0m" + <<-EXPECTED
+Name|Description
+----|---------------
+foo |Foo description
+bar |
+    EXPECTED
+    assert_equal expected, @to.end_accepting
+  end
+
   def accept_table_align
     expected = "\e[0m" + <<-EXPECTED
  AA |BB |CCCCC|DDDDD

test/rdoc/markup/to_bs_test.rb

@@ -349,6 +349,16 @@ def list_verbatim
     assert_equal expected, @to.end_accepting
   end
 
+  def accept_table_ragged_rows
+    expected = <<-EXPECTED
+Name|Description
+----|---------------
+foo |Foo description
+bar |
+    EXPECTED
+    assert_equal expected, @to.end_accepting
+  end
+
   def accept_table_align
     expected = <<-EXPECTED
  AA |BB |CCCCC|DDDDD

test/rdoc/markup/to_markdown_test.rb

@@ -346,6 +346,16 @@ def list_verbatim
     assert_equal expected, @to.end_accepting
   end
 
+  def accept_table_ragged_rows
+    expected = <<-EXPECTED
+Name|Description
+----|---------------
+foo |Foo description
+bar |
+    EXPECTED
+    assert_equal expected, @to.end_accepting
+  end
+
   def accept_table_align
     expected = <<-EXPECTED
  AA |BB |CCCCC|DDDDD

test/rdoc/markup/to_rdoc_test.rb

@@ -375,6 +375,16 @@ def list_verbatim
     assert_equal expected, @to.end_accepting
   end
 
+  def accept_table_ragged_rows
+    expected = <<-EXPECTED
+Name|Description
+----|---------------
+foo |Foo description
+bar |
+    EXPECTED
+    assert_equal expected, @to.end_accepting
+  end
+
   def accept_table_align
     expected = <<-EXPECTED
  AA |BB |   CCCCC|   DDDDD

test/rdoc/support/text_formatter_test_case.rb

@@ -116,6 +116,23 @@ def test_accept_table_align
         accept_table_align
       end
 
+      ##
+      # Test case that calls <tt>@to.accept_table</tt> with body rows
+      # that have fewer columns than the header
+
+      def test_accept_table_ragged_rows
+        header = ['Name', 'Description']
+        body = [
+          ['foo', 'Foo description'],
+          ['bar'],
+        ]
+        aligns = [:left, :left]
+        @to.start_accepting
+        @to.accept_table header, body, aligns
+
+        accept_table_ragged_rows
+      end
+
       ##
       # Test case that calls <tt>@to.attributes</tt> with an escaped
       # cross-reference.  If this test doesn't pass something may be very