gh-36034: Fix block-scoped doctest tags with `\` line continuations
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes #1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->

<!-- Why is this change required? What problem does it solve? -->
Fixes
#36033 (comment)
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes #12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [ ] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- #12345: short description why this is a dependency
- #34567: ...
-->
- Depends on #36025 (merged here)

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #36034
Reported by: Matthias Köppe
Reviewer(s): Kwankyu Lee, Matthias Köppe

Author: Release Manager

src/sage/coding/code_constructions.py

@@ -732,8 +732,7 @@ def ToricCode(P,F):
          sage: C.minimum_distance()
          24
          sage: C.minimum_distance(algorithm="guava")  # optional - gap_package_guava
-         ...
-         24
+         ...24
          sage: C = codes.ToricCode([[-2,-2],[-1,-2],[-1,-1],[-1,0],
          ....:                      [0,-1],[0,0],[0,1],[1,-1],[1,0]], GF(5))
          sage: C

src/sage/coding/linear_code.py

@@ -911,8 +911,7 @@ def covering_radius(self):
 
             sage: C = codes.HammingCode(GF(2), 5)
             sage: C.covering_radius()                           # optional - gap_package_guava
-            ...
-            1
+            ...1
 
             sage: C = codes.random_linear_code(GF(263), 5, 1)
             sage: C.covering_radius()                           # optional - gap_package_guava
@@ -1375,8 +1374,7 @@ def minimum_distance(self, algorithm=None):
             3
             sage: libgap.SetAllInfoLevels(0)         # to suppress extra info messages  # optional - sage.libs.gap
             sage: C.minimum_distance(algorithm="guava")         # optional - gap_package_guava
-            ...
-            3
+            ...3
 
         TESTS::
 

src/sage/doctest/parsing.py

@@ -1071,14 +1071,36 @@ def parse(self, string, *args):
             '',
             (None, '5 # optional guava\n', 'Integer(5) # optional guava\n'),
             '']
+
+        TESTS::
+
+            sage: parse("::\n\n    sage: # needs sage.combinat\n    sage: from sage.geometry.polyhedron.combinatorial_polyhedron.conversions \\\n    ....:         import incidence_matrix_to_bit_rep_of_Vrep\n    sage: P = polytopes.associahedron(['A',3])\n\n")
+            ['::\n\n',
+            '',
+            (None,
+            'from sage.geometry.polyhedron.combinatorial_polyhedron.conversions import incidence_matrix_to_bit_rep_of_Vrep\n',
+            'from sage.geometry.polyhedron.combinatorial_polyhedron.conversions import incidence_matrix_to_bit_rep_of_Vrep\n'),
+            '',
+            (None,
+            "P = polytopes.associahedron(['A',3])\n",
+            "P = polytopes.associahedron(['A',Integer(3)])\n"),
+            '\n']
+
+            sage: example4 = '::\n\n        sage: C.minimum_distance(algorithm="guava")  # optional - guava\n        ...\n        24\n\n'
+            sage: parsed4 = DTP.parse(example4)
+            sage: dte = parsed4[1]
+            sage: dte.sage_source
+            'C.minimum_distance(algorithm="guava")  # optional - guava\n'
+            sage: dte.want
+            '...\n24\n'
         """
         # Regular expressions
         find_sage_prompt = re.compile(r"^(\s*)sage: ", re.M)
         find_sage_continuation = re.compile(r"^(\s*)\.\.\.\.:", re.M)
         find_python_continuation = re.compile(r"^(\s*)\.\.\.([^\.])", re.M)
         python_prompt = re.compile(r"^(\s*)>>>", re.M)
         backslash_replacer = re.compile(r"""(\s*)sage:(.*)\\\ *
-\ *(((\.){4}:)|((\.){3}))?\ *""")
+\ *((\.){4}:)?\ *""")
 
         # The following are used to allow ... at the beginning of output
         ellipsis_tag = "<TEMP_ELLIPSIS_TAG>"
@@ -1087,13 +1109,8 @@ def parse(self, string, *args):
         # doctest system.
         m = backslash_replacer.search(string)
         while m is not None:
-            next_prompt = find_sage_prompt.search(string, m.end())
             g = m.groups()
-            if next_prompt:
-                future = string[m.end():next_prompt.start()] + '\n' + string[next_prompt.start():]
-            else:
-                future = string[m.end():]
-            string = string[:m.start()] + g[0] + "sage:" + g[1] + future
+            string = string[:m.start()] + g[0] + "sage:" + g[1] + string[m.end():]
             m = backslash_replacer.search(string, m.start())
 
         replace_ellipsis = not python_prompt.search(string)

src/sage/dynamics/arithmetic_dynamics/wehlerK3.py

@@ -474,7 +474,7 @@ def Qxa(self, a):
            sage: Z = x0^2*y0^2 + 3*x0*x1*y0^2 + x1^2*y0^2 + 4*x0^2*y0*y1 + 3*x0*x1*y0*y1 \
            - 2*x2^2*y0*y1 - x0^2*y1^2 + 2*x1^2*y1^2 - x0*x2*y1^2 - 4*x1*x2*y1^2 \
            + 5*x0*x2*y0*y2 \
-           - 4*x1*x2*y0*y2 + 7*x0^2*y1*y2 + 4*x1^2*y1*y2 + x0*x1*y2^2 + 3*x2^2*y2^2 \
+           - 4*x1*x2*y0*y2 + 7*x0^2*y1*y2 + 4*x1^2*y1*y2 + x0*x1*y2^2 + 3*x2^2*y2^2
            sage: Y = x0*y0 + x1*y1 + x2*y2
            sage: X = WehlerK3Surface([Z, Y])
            sage: T = PP(1, 1, 0, 1, 0, 0)

src/sage/symbolic/expression.pyx

@@ -238,7 +238,7 @@ Check that :trac:`9880` is fixed::
     11/27*b_0/((2^b_2)^2*(2^b_1)^2*(2^b_0)^2) - \
     11/27*b_1/((2^b_2)^2*(2^b_1)^2*(2^b_0)^2) - \
     11/27*b_2/((2^b_2)^2*(2^b_1)^2*(2^b_0)^2) + \
-    64/81/((2^b_2)^2*(2^b_1)^2*(2^b_0)^2) + 35/81 \
+    64/81/((2^b_2)^2*(2^b_1)^2*(2^b_0)^2) + 35/81
     sage: f.nops()
     38
 

src/sage/tests/book_stein_ent.py

@@ -21,10 +21,10 @@
 sage: factor(31415926535898)
 2 * 3 * 53 * 73 * 2531 * 534697
 sage: n = 7403756347956171282804679609742957314259318888\
-...9231289084936232638972765034028266276891996419625117\
-...8439958943305021275853701189680982867331732731089309\
-...0055250511687706329907239638078671008609696253793465\
-...0563796359
+....: 9231289084936232638972765034028266276891996419625117\
+....: 8439958943305021275853701189680982867331732731089309\
+....: 0055250511687706329907239638078671008609696253793465\
+....: 0563796359
 sage: len(n.str(2))
 704
 sage: len(n.str(10))