Cleanup copilot code

src/calibre/utils/icu.c

@@ -1666,15 +1666,13 @@ icu_word_prefix_find(PyObject *self, PyObject *args) {
     x_icu = python_to_icu(x_, &xsz);
     if (x_icu == NULL) return NULL;
     it->counter++;
-    if (it->text != NULL) { free(it->text); it->text = NULL; it->text_len = 0; }
     ubrk_setText(it->break_iterator, x_icu, xsz, &status);
     if (U_FAILURE(status)) {
         free(x_icu);
         PyErr_SetString(PyExc_ValueError, u_errorName(status));
         return NULL;
     }
-    it->text = x_icu; it->text_len = xsz;
-    x_icu = NULL;  // ownership transferred to it->text
+    free(it->text); it->text = x_icu; it->text_len = xsz; x_icu = NULL;  // ownership transferred to it->text
 
     // Convert prefix to ICU once
     prefix_icu = python_to_icu(prefix_, &prefix_sz);

src/calibre/utils/icu.py

@@ -239,7 +239,15 @@ startswith = make_two_arg_func(collator, 'startswith')
 primary_startswith = make_two_arg_func(primary_collator, 'startswith')
 safe_chr = _icu.chr
 ord_string = _icu.ord_string
-word_prefix_find = _icu.word_prefix_find
+try:
+    word_prefix_find = _icu.word_prefix_find
+except AttributeError:  # people running from source
+    def word_prefix_find(collator, it, x, prefix):
+        it.set_text(x)
+        for pos, size in it.split2():
+            if collator.startswith(x, prefix, pos):
+                return pos
+        return -1
 
 
 def character_name(string):

src/calibre/utils/icu_test.py

@@ -287,6 +287,7 @@ class TestICU(unittest.TestCase):
         self.ae(wpf(c, it, 'hello world', 'he'), 0)
         self.ae(wpf(c, it, 'hello world', 'world'), 6)
         self.ae(wpf(c, it, 'hello world', 'hello'), 0)
+        self.ae(wpf(c, it, 'masi asim', 'asi'), 5)
         # No match returns -1
         self.ae(wpf(c, it, 'hello world', 'xyz'), -1)
         # Case-insensitive match with primary collator