Handle positions when matching on non BMP chars on narrow python builds correctly

src/calibre/gui2/tweak_book/widgets.py

@@ -17,6 +17,7 @@ from PyQt4.Qt import (
 from calibre import prepare_string_for_xml
 from calibre.gui2 import error_dialog, choose_files, choose_save_file
 from calibre.gui2.tweak_book import tprefs
+from calibre.utils.matcher import get_char, Matcher
 
 class Dialog(QDialog):
 
@@ -309,7 +310,8 @@ class Results(QWidget):
         positions = sorted(set(positions) - {-1}, reverse=True)
         text = prepare_string_for_xml(text)
         for p in positions:
-            text = '%s<span style="%s">%s</span>%s' % (text[:p], self.EMPH, text[p], text[p+1:])
+            ch = get_char(text, p)
+            text = '%s<span style="%s">%s</span>%s' % (text[:p], self.EMPH, ch, text[p+len(ch):])
         text = QStaticText(text)
         text.setTextFormat(Qt.RichText)
         return text
@@ -363,7 +365,6 @@ class Results(QWidget):
 class QuickOpen(Dialog):
 
     def __init__(self, items, parent=None):
-        from calibre.utils.matcher import Matcher
         self.matcher = Matcher(items)
         self.matches = ()
         self.selected_result = None

src/calibre/utils/matcher.c

@@ -155,6 +155,10 @@ static double calc_score_for_char(MatchInfo *m, UChar32 last, UChar32 current, i
 }
 
 static void convert_positions(int32_t *positions, int32_t *final_positions, UChar *string, int32_t char_len, int32_t byte_len, double score) {
+#if PY_VERSION_HEX >= 0x03030000 
+#error Not implemented for python >= 3.3
+#endif
+
     // The positions array stores character positions as byte offsets in string, convert them into character offsets
     int32_t i, *end;
 
@@ -163,7 +167,11 @@ static void convert_positions(int32_t *positions, int32_t *final_positions, UCha
     end = final_positions + char_len;
     for (i = 0; i < byte_len && final_positions < end; i++) {
         if (positions[i] == -1) continue;
+#ifdef Py_UNICODE_WIDE
         *final_positions = u_countChar32(string, positions[i]);
+#else
+        *final_positions = positions[i];
+#endif
         final_positions += 1;
     }
 }

src/calibre/utils/matcher.py

@@ -139,6 +139,7 @@ class FilesystemMatcher(Matcher):
     def __init__(self, basedir, *args, **kwargs):
         Matcher.__init__(self, get_items_from_dir(basedir), *args, **kwargs)
 
+# Python implementation of the scoring algorithm {{{
 def calc_score_for_char(ctx, prev, current, distance):
     factor = 1.0
     ans = ctx.max_score_per_char
@@ -202,11 +203,11 @@ class PyScorer(object):
             self.max_score_per_char = (1.0 / len(item) + 1.0 / len(needle)) / 2.0
             self.memory = {}
             yield process_item(self, item, needle)
+# }}}
 
 class CScorer(object):
 
     def __init__(self, items, level1=DEFAULT_LEVEL1, level2=DEFAULT_LEVEL2, level3=DEFAULT_LEVEL3):
-
         speedup, err = plugins['matcher']
         if speedup is None:
             raise PluginFailed('Failed to load the matcher plugin with error: %s' % err)
@@ -217,14 +218,6 @@ class CScorer(object):
         for score, pos in izip(scores, positions):
             yield score, pos
 
-def test2():
-    items = ['.driveinfo.calibre', 'Suspense.xls', 'p/parsed/content.opf', 'ns.html']
-    for q in (PyScorer, CScorer):
-        print (q)
-        m = Matcher(items, scorer=q)
-        for item, positions in m('ns').iteritems():
-            print ('\tns', item, positions)
-
 def test():
     items = ['mx\U0001f431nxox']
     for q in (PyScorer, CScorer):
@@ -237,7 +230,6 @@ def test():
                     print (item[p], end=' ')
                 print ()
 
-
 def test_mem():
     from calibre.utils.mem import gc_histogram, diff_hists
     m = Matcher(['a'])
@@ -255,6 +247,13 @@ def test_mem():
     h2 = gc_histogram()
     diff_hists(h1, h2)
 
+if sys.maxunicode >= 0x10ffff:
+    get_char = lambda string, pos: string[pos]
+else:
+    def get_char(string, pos):
+        chs = 2 if ('\ud800' <= string[pos] <= '\udbff') else 1  # UTF-16 surrogate pair in python narrow builds
+        return string[pos:pos+chs]
+
 def main(basedir=None, query=None):
     from calibre import prints
     from calibre.utils.terminal import ColoredStream
@@ -279,11 +278,12 @@ def main(basedir=None, query=None):
             while positions:
                 pos = positions.pop(0)
                 if pos == -1:
-                    break
+                    continue
                 prints(path[p:pos], end='')
+                ch = get_char(path, pos)
                 with emph:
-                    prints(path[pos], end='')
-                p = pos + 1
+                    prints(ch, end='')
+                p = pos + len(ch)
             prints(path[p:])
         query = None