fix infinite loop in TextHelpAppendable.makeColumnQueue at width 1

src/main/java/org/apache/commons/cli/help/TextHelpAppendable.java

@@ -99,8 +99,9 @@ public static int indexOfWrap(final CharSequence text, final int width, final in
                 break;
             }
         }
-        // if we found it return it, otherwise just chop at limit
-        return pos > startPos ? pos : limit - 1;
+        // if we found it return it, otherwise just chop at limit, always consuming at least one character so that a width of 1
+        // still advances past startPos and the wrap loop in makeColumnQueue terminates.
+        return pos > startPos ? pos : Math.max(limit - 1, startPos + 1);
     }
 
     /**
@@ -218,12 +219,14 @@ public void appendHeader(final int level, final CharSequence text) throws IOExce
     @Override
     public void appendList(final boolean ordered, final Collection<CharSequence> list) throws IOException {
         if (list != null && !list.isEmpty()) {
-            final TextStyle.Builder builder = TextStyle.builder().setLeftPad(textStyleBuilder.getLeftPad()).setIndent(DEFAULT_LIST_INDENT);
+            // wrap at the configured width rather than the entry length: an entry with a line break that is shorter than the
+            // list indent would otherwise leave no room for its continuation lines.
+            final TextStyle.Builder builder = TextStyle.builder().setLeftPad(textStyleBuilder.getLeftPad()).setIndent(DEFAULT_LIST_INDENT)
+                    .setMaxWidth(textStyleBuilder.getMaxWidth());
             int i = 1;
             for (final CharSequence line : list) {
                 final String entry = ordered ? String.format(" %s. %s", i++, Util.defaultValue(line, BLANK_LINE))
                         : String.format(" * %s", Util.defaultValue(line, BLANK_LINE));
-                builder.setMaxWidth(Math.min(textStyleBuilder.getMaxWidth(), entry.length()));
                 printQueue(makeColumnQueue(entry, builder.get()));
             }
             output.append(System.lineSeparator());

src/test/java/org/apache/commons/cli/help/TextHelpAppendableTest.java

@@ -157,6 +157,21 @@ void testAppendList() throws IOException {
         assertEquals(expected, actual, "null list failed");
     }
 
+    @Test
+    void testAppendListWithLineBreak() throws IOException {
+        // an entry shorter than the list indent used to throw and an 8 character entry used to loop until the heap was exhausted
+        final List<String> expected = new ArrayList<>();
+        expected.add("  * a");
+        expected.add("        b");
+        expected.add("  * ab");
+        expected.add("        cd");
+        expected.add("");
+
+        underTest.appendList(false, Arrays.asList("a\nb", "ab\ncd"));
+        final List<String> actual = IOUtils.readLines(new StringReader(sb.toString()));
+        assertEquals(expected, actual);
+    }
+
     @Test
     void testAppendParagraph() throws IOException {
         final String[] expected = { " Hello World", "" };
@@ -281,6 +296,10 @@ void testindexOfWrapPos() {
         assertThrows(IllegalArgumentException.class, () -> TextHelpAppendable.indexOfWrap("", 0, 0));
         assertEquals(3, TextHelpAppendable.indexOfWrap("Hello", 4, 0));
 
+        // a width of 1 must still consume one character, otherwise makeColumnQueue never advances
+        assertEquals(1, TextHelpAppendable.indexOfWrap("Hello", 1, 0), "width of 1 did not advance");
+        assertEquals(3, TextHelpAppendable.indexOfWrap("Hello", 1, 2), "width of 1 did not advance past startPos");
+
         // startPos + width must not overflow when width is TextStyle.UNSET_MAX_WIDTH
         assertEquals(30, TextHelpAppendable.indexOfWrap(testString, TextStyle.UNSET_MAX_WIDTH, 0), "did not find break character with unbounded width");
         assertEquals(testString.length(), TextHelpAppendable.indexOfWrap(testString, TextStyle.UNSET_MAX_WIDTH, 31), "overflow produced a negative wrap index");
@@ -357,6 +376,24 @@ void testMakeColumnQueueWithMultipleTrailingLineBreaks() {
         assertEquals(expected, result, "left aligned failed");
     }
 
+    @Test
+    void testMakeColumnQueueWithWidthOfOne() {
+        // an indent one less than the max width leaves a usable width of 1 for the continuation lines, which used to loop forever
+        final String text = "hello world";
+        final TextStyle.Builder styleBuilder = TextStyle.builder().setMaxWidth(5).setIndent(4).setLeftPad(0);
+
+        final Queue<String> expected = new LinkedList<>();
+        expected.add("hello");
+        expected.add("    w");
+        expected.add("    o");
+        expected.add("    r");
+        expected.add("    l");
+        expected.add("    d");
+
+        final Queue<String> result = underTest.makeColumnQueue(text, styleBuilder.get());
+        assertEquals(expected, result);
+    }
+
     @Test
     void testPrintWrapped() throws IOException {
         String text = "The quick brown fox jumps over the lazy dog";