src/ tests/: avoid infinite loop in fill_textbox() if word is too long.

Addresses #4400.

Author: julian-smith-artifex-com

src/utils.py

@@ -4610,12 +4610,12 @@ def output_justify(start, line):
         words = line.split(" ")  # the words in the line
 
         # cut in parts any words that are longer than rect width
-        words, word_lengths = norm_words(std_width, words)
+        words, word_lengths = norm_words(width, words)
 
         n = len(words)
         while True:
             line0 = " ".join(words[:n])
-            wl = sum(word_lengths[:n]) + space_len * (len(word_lengths[:n]) - 1)
+            wl = sum(word_lengths[:n]) + space_len * (n - 1)
             if wl <= width:
                 new_lines.append((line0, wl))
                 words = words[n:]
@@ -4627,6 +4627,7 @@ def output_justify(start, line):
 
             if len(words) == 0:
                 break
+            assert n
 
     # -------------------------------------------------------------------------
     # List of lines created. Each item is (text, tl), where 'tl' is the PDF

tests/test_general.py

@@ -1669,4 +1669,4 @@ def test_3886():
     rms_0 = gentle_compare.pixmaps_rms(pixmap, pixmap_clean0)
     rms_1 = gentle_compare.pixmaps_rms(pixmap, pixmap_clean1)
     print(f'test_3886(): {rms_0=} {rms_1=}')
-        
+

tests/test_textbox.py

@@ -280,3 +280,12 @@ def test_3916():
     page = doc.new_page()
     spare_height, scale = page.insert_htmlbox(rect, "Hello, World!", scale_low=0.5)
     assert spare_height == -1
+
+
+def test_4400():
+    with pymupdf.open() as document:
+        page = document.new_page()
+        writer = pymupdf.TextWriter(page.rect)
+        text = '111111111'
+        print(f'Calling writer.fill_textbox().', flush=1)
+        writer.fill_textbox(rect=pymupdf.Rect(0, 0, 100, 20), pos=(80, 0), text=text, fontsize=8)