Fix T71774: SVG import error on specific files

Was happening if the software which wrote SVG skipped decimal part.

io_curve_svg/svg_util.py

@@ -46,14 +46,14 @@ def check_points_equal(point_a, point_b):
             abs(point_a[1] - point_b[1]) < 1e-6)
 
 match_number = r"-?\d+(\.\d+)?([eE][-+]?\d+)?"
-match_number_optional_fractional = r"-?\d+(\.\d*)?([eE][-+]?\d+)?"
 match_first_comma = r"^\s*(?=,)"
 match_comma_pair = r",\s*(?=,)"
 match_last_comma = r",\s*$"
 
-re_match_number_optional_fractional = re.compile(match_number_optional_fractional)
+match_number_optional_parts = r"(-?\d+(\.\d*)?([eE][-+]?\d+)?)|(-?\.\d+([eE][-+]?\d+)?)"
+re_match_number_optional_parts = re.compile(match_number_optional_parts)
 
-array_of_floats_pattern = f"({match_number})|{match_first_comma}|{match_comma_pair}|{match_last_comma}"
+array_of_floats_pattern = f"({match_number_optional_parts})|{match_first_comma}|{match_comma_pair}|{match_last_comma}"
 re_array_of_floats_pattern = re.compile(array_of_floats_pattern)
 
 def parse_array_of_floats(text):
@@ -82,7 +82,7 @@ def read_float(text: str, start_index: int = 0):
         return "0", start_index
 
     text_part = text[start_index:]
-    match = re_match_number_optional_fractional.match(text_part)
+    match = re_match_number_optional_parts.match(text_part)
 
     if match is None:
         raise Exception('Invalid float value near ' + text[start_index:start_index + 10])

io_curve_svg/svg_util_test.py

@@ -29,7 +29,6 @@ else:
     from .svg_util import (parse_array_of_floats, read_float, parse_coord,)
 import unittest
 
-
 class ParseArrayOfFloatsTest(unittest.TestCase):
     def test_empty(self):
         self.assertEqual(parse_array_of_floats(""), [])
@@ -78,6 +77,13 @@ class ParseArrayOfFloatsTest(unittest.TestCase):
     def test_comma_separated_values_with_decimal_separator(self):
         self.assertEqual(parse_array_of_floats("2.75,8.5"), [2.75, 8.5])
 
+    def test_missing_decimal(self):
+        self.assertEqual(parse_array_of_floats(".92"), [0.92])
+        self.assertEqual(parse_array_of_floats(".92e+1"), [9.2])
+
+        self.assertEqual(parse_array_of_floats("-.92"), [-0.92])
+        self.assertEqual(parse_array_of_floats("-.92e+1"), [-9.2])
+
 
 class ReadFloatTest(unittest.TestCase):
     def test_empty(self):
@@ -116,7 +122,7 @@ class ReadFloatTest(unittest.TestCase):
         self.assertEqual(endptr, 10)
 
     def test_not_a_number(self):
-        # TODO(sergey): Make this more concrete.
+        # TODO(sergey): Make this catch more concrete.
         with self.assertRaises(Exception):
             read_float("1.2eV", 3)
 
@@ -129,6 +135,29 @@ class ReadFloatTest(unittest.TestCase):
         self.assertEqual(value, "2.")
         self.assertEqual(endptr, 2)
 
+    def test_missing_decimal(self):
+        value, endptr = read_float(".92", 0)
+        self.assertEqual(value, ".92")
+        self.assertEqual(endptr, 3)
+
+        value, endptr = read_float("-.92", 0)
+        self.assertEqual(value, "-.92")
+        self.assertEqual(endptr, 4)
+
+        value, endptr = read_float(".92e+3", 0)
+        self.assertEqual(value, ".92e+3")
+        self.assertEqual(endptr, 6)
+
+        value, endptr = read_float("-.92e+3", 0)
+        self.assertEqual(value, "-.92e+3")
+        self.assertEqual(endptr, 7)
+
+        # TODO(sergey): Make these catch more concrete.
+        with self.assertRaises(Exception):
+            read_float(".", 0)
+        with self.assertRaises(Exception):
+            read_float(".e+1", 0)
+
 
 class ParseCoordTest(unittest.TestCase):
     def test_empty(self):