We are currently solving the following issue within our repository. Here is the issue text:
--- BEGIN ISSUE ---
Recaser bug: adding fixed-case inside tex-math markup
`<tex-math><fixed-case>O</fixed-case>(<fixed-case>M</fixed-case>(n^2))</tex-math>` caused the build to fail in #892

--- END ISSUE ---

Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
--- BEGIN FILES ---
Path: `bin/fixedcase/protect.py`
Content:
```
1 #!/usr/bin/env python3
2 
3 # protect.py <infile> <outfile>
4 # looks for file "truelist" in current dir
5 
6 # cd data/xml
7 # for i in *xml ; do (cd ../../tools/fixedcase/ ; python3 ./protect.py ../../data/xml/$i /tmp/$i ; echo $i ); done > log
8 
9 
10 import lxml.etree as ET
11 import os
12 import sys
13 import copy
14 import itertools
15 import inspect
16 
17 from collections import defaultdict
18 
19 if __name__ == "__main__":
20     from common import *
21 else:
22     from .common import *
23 
24 # recursive helper called by protect
25 # protect text of "node", including children, and tails of children
26 def protect_recurse(node, recased):
27     if node.tag == "fixed-case":  # already protected
28         newnode = copy.deepcopy(node)  # don't need to modify descendents
29         newnode.tail = None  # tail will be protected by caller
30         return newnode
31     newnode = ET.Element(node.tag, node.attrib)
32 
33     def process(text, rc):
34         i = 0
35         for upper, chars in itertools.groupby(rc[: len(text)], lambda c: c.isupper()):
36             charstr = "".join(chars)
37             if upper:
38                 p = ET.Element("fixed-case")
39                 p.text = charstr
40                 newnode.append(p)
41             else:
42                 append_text(newnode, text[i : i + len(charstr)])
43 
44             assert text[i : i + len(charstr)].lower() == charstr.lower(), (
45                 i,
46                 text,
47                 charstr,
48             )
49             i += len(charstr)
50 
51     if node.text:
52         process(node.text, recased)
53         recased = recased[len(node.text) :]
54     for child in node:
55         protected_child = protect_recurse(child, recased)
56         recased = recased[len(get_text(protected_child)) :]
57         newnode.append(protected_child)
58         if child.tail:
59             process(child.tail, recased)
60             recased = recased[len(child.tail) :]
61 
62     return newnode
63 
64 
65 def protect(node):
66     rawtext = get_text(node).strip()
67     recased = None
68     if rawtext.lower() in special_titles:
69         recased = special_titles[rawtext.lower()]
70     else:
71         text = tokenize(rawtext)
72         fixed = fixedcase_title(
73             text,
74             truelist=truelist,
75             phrase_truelist=phrase_truelist,
76             amodifiers=amodifiers,
77             ndescriptors=ndescriptors,
78         )
79         if any(fixed):
80             # Generate the recased string so we know where to look in the XML
81             # to apply fixed-case
82             recasedtoks = [(w if b else w.lower()) for w, b in zip(text, fixed)]
83             recased = TreebankWordDetokenizer().detokenize(recasedtoks)
84             # PTB (de)tokenizer doesn't think of hyphens as separate tokens,
85             # so we need to manually detokenize them.
86             # Assuming the only edits that need to be made are adding/deleting
87             # spaces, the following will work:
88             i = 0
89             while i < len(rawtext):
90                 # scan rawtext from left to right and adjust recased by adding/removing
91                 # spaces until it matches
92                 t = rawtext[i]
93                 assert i < len(recased), ((i, t), rawtext, recased)
94                 c = recased[i]
95                 if t.isspace() and not c.isspace():  # may be ' ' or '\n'
96                     # add space to recased
97                     recased = recased[:i] + t + recased[i:]
98                     i += 1
99                 elif c.isspace() and not t.isspace():
100                     # remove space from recased
101                     recased = recased[:i] + recased[i + 1 :]
102                     # don't increment i
103                 elif t != c and t.isspace() and c.isspace():
104                     recased = recased[:i] + t + recased[i + 1 :]
105                     i += 1
106                 else:
107                     assert t == c or t.lower() == c.lower(), (
108                         (i, t, c),
109                         rawtext,
110                         recased,
111                         text,
112                     )
113                     i += 1
114             if len(recased) > len(rawtext):
115                 recased = recased[: len(rawtext)]
116             assert rawtext.lower() == recased.lower(), (rawtext, recased)
117 
118     if recased:
119         newnode = protect_recurse(node, recased)
120         newnode.tail = node.tail  # tail of top level is not protected
121         replace_node(node, newnode)
122 
123 
124 # Read in the truelist (list of words that should always be protected)
125 truelist, phrase_truelist, special_titles, amodifiers, ndescriptors = load_lists()
126 
127 if __name__ == "__main__":
128     infile, outfile = sys.argv[1:]
129 
130     tree = ET.parse(infile)
131     if not tree.getroot().tail:
132         tree.getroot().tail = "\n"
133     for paper in tree.getroot().findall(".//paper"):
134         for title in paper.xpath("./title|./booktitle"):
135             protect(title)
136     tree.write(outfile, encoding="UTF-8", xml_declaration=True)
137
```
--- END FILES ---

Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.

Here is an example:

```diff
diff --git a/examples/server_async.py b/examples/server_async.py
--- a/examples/server_async.py
+++ b/examples/server_async.py
@@ -313,4 +313,4 @@
 
 
 if __name__ == "__main__":
-    asyncio.run(run_async_server("."), debug=True)
+    asyncio.run(run_async_server(), debug=True)
diff --git a/examples/server_sync.py b/examples/server_sync.py
--- a/examples/server_sync.py
+++ b/examples/server_sync.py
@@ -313,5 +313,5 @@
 
 
 if __name__ == "__main__":
-    server = run_sync_server(".")
+    server = run_sync_server()
     server.shutdown()

```

diff --git a/bin/fixedcase/protect.py b/bin/fixedcase/protect.py
--- a/bin/fixedcase/protect.py
+++ b/bin/fixedcase/protect.py
@@ -24,7 +24,7 @@
 # recursive helper called by protect
 # protect text of "node", including children, and tails of children
 def protect_recurse(node, recased):
-    if node.tag == "fixed-case":  # already protected
+    if node.tag in ("fixed-case", "tex-math"):  # already protected text, or math
         newnode = copy.deepcopy(node)  # don't need to modify descendents
         newnode.tail = None  # tail will be protected by caller
         return newnode

{"golden_diff": "diff --git a/bin/fixedcase/protect.py b/bin/fixedcase/protect.py\n--- a/bin/fixedcase/protect.py\n+++ b/bin/fixedcase/protect.py\n@@ -24,7 +24,7 @@\n # recursive helper called by protect\n # protect text of \"node\", including children, and tails of children\n def protect_recurse(node, recased):\n-    if node.tag == \"fixed-case\":  # already protected\n+    if node.tag in (\"fixed-case\", \"tex-math\"):  # already protected text, or math\n         newnode = copy.deepcopy(node)  # don't need to modify descendents\n         newnode.tail = None  # tail will be protected by caller\n         return newnode\n", "issue": "Recaser bug: adding fixed-case inside tex-math markup\n`<tex-math><fixed-case>O</fixed-case>(<fixed-case>M</fixed-case>(n^2))</tex-math>` caused the build to fail in #892\n", "before_files": [{"content": "#!/usr/bin/env python3\n\n# protect.py <infile> <outfile>\n# looks for file \"truelist\" in current dir\n\n# cd data/xml\n# for i in *xml ; do (cd ../../tools/fixedcase/ ; python3 ./protect.py ../../data/xml/$i /tmp/$i ; echo $i ); done > log\n\n\nimport lxml.etree as ET\nimport os\nimport sys\nimport copy\nimport itertools\nimport inspect\n\nfrom collections import defaultdict\n\nif __name__ == \"__main__\":\n    from common import *\nelse:\n    from .common import *\n\n# recursive helper called by protect\n# protect text of \"node\", including children, and tails of children\ndef protect_recurse(node, recased):\n    if node.tag == \"fixed-case\":  # already protected\n        newnode = copy.deepcopy(node)  # don't need to modify descendents\n        newnode.tail = None  # tail will be protected by caller\n        return newnode\n    newnode = ET.Element(node.tag, node.attrib)\n\n    def process(text, rc):\n        i = 0\n        for upper, chars in itertools.groupby(rc[: len(text)], lambda c: c.isupper()):\n            charstr = \"\".join(chars)\n            if upper:\n                p = ET.Element(\"fixed-case\")\n                p.text = charstr\n                newnode.append(p)\n            else:\n                append_text(newnode, text[i : i + len(charstr)])\n\n            assert text[i : i + len(charstr)].lower() == charstr.lower(), (\n                i,\n                text,\n                charstr,\n            )\n            i += len(charstr)\n\n    if node.text:\n        process(node.text, recased)\n        recased = recased[len(node.text) :]\n    for child in node:\n        protected_child = protect_recurse(child, recased)\n        recased = recased[len(get_text(protected_child)) :]\n        newnode.append(protected_child)\n        if child.tail:\n            process(child.tail, recased)\n            recased = recased[len(child.tail) :]\n\n    return newnode\n\n\ndef protect(node):\n    rawtext = get_text(node).strip()\n    recased = None\n    if rawtext.lower() in special_titles:\n        recased = special_titles[rawtext.lower()]\n    else:\n        text = tokenize(rawtext)\n        fixed = fixedcase_title(\n            text,\n            truelist=truelist,\n            phrase_truelist=phrase_truelist,\n            amodifiers=amodifiers,\n            ndescriptors=ndescriptors,\n        )\n        if any(fixed):\n            # Generate the recased string so we know where to look in the XML\n            # to apply fixed-case\n            recasedtoks = [(w if b else w.lower()) for w, b in zip(text, fixed)]\n            recased = TreebankWordDetokenizer().detokenize(recasedtoks)\n            # PTB (de)tokenizer doesn't think of hyphens as separate tokens,\n            # so we need to manually detokenize them.\n            # Assuming the only edits that need to be made are adding/deleting\n            # spaces, the following will work:\n            i = 0\n            while i < len(rawtext):\n                # scan rawtext from left to right and adjust recased by adding/removing\n                # spaces until it matches\n                t = rawtext[i]\n                assert i < len(recased), ((i, t), rawtext, recased)\n                c = recased[i]\n                if t.isspace() and not c.isspace():  # may be ' ' or '\\n'\n                    # add space to recased\n                    recased = recased[:i] + t + recased[i:]\n                    i += 1\n                elif c.isspace() and not t.isspace():\n                    # remove space from recased\n                    recased = recased[:i] + recased[i + 1 :]\n                    # don't increment i\n                elif t != c and t.isspace() and c.isspace():\n                    recased = recased[:i] + t + recased[i + 1 :]\n                    i += 1\n                else:\n                    assert t == c or t.lower() == c.lower(), (\n                        (i, t, c),\n                        rawtext,\n                        recased,\n                        text,\n                    )\n                    i += 1\n            if len(recased) > len(rawtext):\n                recased = recased[: len(rawtext)]\n            assert rawtext.lower() == recased.lower(), (rawtext, recased)\n\n    if recased:\n        newnode = protect_recurse(node, recased)\n        newnode.tail = node.tail  # tail of top level is not protected\n        replace_node(node, newnode)\n\n\n# Read in the truelist (list of words that should always be protected)\ntruelist, phrase_truelist, special_titles, amodifiers, ndescriptors = load_lists()\n\nif __name__ == \"__main__\":\n    infile, outfile = sys.argv[1:]\n\n    tree = ET.parse(infile)\n    if not tree.getroot().tail:\n        tree.getroot().tail = \"\\n\"\n    for paper in tree.getroot().findall(\".//paper\"):\n        for title in paper.xpath(\"./title|./booktitle\"):\n            protect(title)\n    tree.write(outfile, encoding=\"UTF-8\", xml_declaration=True)\n", "path": "bin/fixedcase/protect.py"}], "after_files": [{"content": "#!/usr/bin/env python3\n\n# protect.py <infile> <outfile>\n# looks for file \"truelist\" in current dir\n\n# cd data/xml\n# for i in *xml ; do (cd ../../tools/fixedcase/ ; python3 ./protect.py ../../data/xml/$i /tmp/$i ; echo $i ); done > log\n\n\nimport lxml.etree as ET\nimport os\nimport sys\nimport copy\nimport itertools\nimport inspect\n\nfrom collections import defaultdict\n\nif __name__ == \"__main__\":\n    from common import *\nelse:\n    from .common import *\n\n# recursive helper called by protect\n# protect text of \"node\", including children, and tails of children\ndef protect_recurse(node, recased):\n    if node.tag in (\"fixed-case\", \"tex-math\"):  # already protected text, or math\n        newnode = copy.deepcopy(node)  # don't need to modify descendents\n        newnode.tail = None  # tail will be protected by caller\n        return newnode\n    newnode = ET.Element(node.tag, node.attrib)\n\n    def process(text, rc):\n        i = 0\n        for upper, chars in itertools.groupby(rc[: len(text)], lambda c: c.isupper()):\n            charstr = \"\".join(chars)\n            if upper:\n                p = ET.Element(\"fixed-case\")\n                p.text = charstr\n                newnode.append(p)\n            else:\n                append_text(newnode, text[i : i + len(charstr)])\n\n            assert text[i : i + len(charstr)].lower() == charstr.lower(), (\n                i,\n                text,\n                charstr,\n            )\n            i += len(charstr)\n\n    if node.text:\n        process(node.text, recased)\n        recased = recased[len(node.text) :]\n    for child in node:\n        protected_child = protect_recurse(child, recased)\n        recased = recased[len(get_text(protected_child)) :]\n        newnode.append(protected_child)\n        if child.tail:\n            process(child.tail, recased)\n            recased = recased[len(child.tail) :]\n\n    return newnode\n\n\ndef protect(node):\n    rawtext = get_text(node).strip()\n    recased = None\n    if rawtext.lower() in special_titles:\n        recased = special_titles[rawtext.lower()]\n    else:\n        text = tokenize(rawtext)\n        fixed = fixedcase_title(\n            text,\n            truelist=truelist,\n            phrase_truelist=phrase_truelist,\n            amodifiers=amodifiers,\n            ndescriptors=ndescriptors,\n        )\n        if any(fixed):\n            # Generate the recased string so we know where to look in the XML\n            # to apply fixed-case\n            recasedtoks = [(w if b else w.lower()) for w, b in zip(text, fixed)]\n            recased = TreebankWordDetokenizer().detokenize(recasedtoks)\n            # PTB (de)tokenizer doesn't think of hyphens as separate tokens,\n            # so we need to manually detokenize them.\n            # Assuming the only edits that need to be made are adding/deleting\n            # spaces, the following will work:\n            i = 0\n            while i < len(rawtext):\n                # scan rawtext from left to right and adjust recased by adding/removing\n                # spaces until it matches\n                t = rawtext[i]\n                assert i < len(recased), ((i, t), rawtext, recased)\n                c = recased[i]\n                if t.isspace() and not c.isspace():  # may be ' ' or '\\n'\n                    # add space to recased\n                    recased = recased[:i] + t + recased[i:]\n                    i += 1\n                elif c.isspace() and not t.isspace():\n                    # remove space from recased\n                    recased = recased[:i] + recased[i + 1 :]\n                    # don't increment i\n                elif t != c and t.isspace() and c.isspace():\n                    recased = recased[:i] + t + recased[i + 1 :]\n                    i += 1\n                else:\n                    assert t == c or t.lower() == c.lower(), (\n                        (i, t, c),\n                        rawtext,\n                        recased,\n                        text,\n                    )\n                    i += 1\n            if len(recased) > len(rawtext):\n                recased = recased[: len(rawtext)]\n            assert rawtext.lower() == recased.lower(), (rawtext, recased)\n\n    if recased:\n        newnode = protect_recurse(node, recased)\n        newnode.tail = node.tail  # tail of top level is not protected\n        replace_node(node, newnode)\n\n\n# Read in the truelist (list of words that should always be protected)\ntruelist, phrase_truelist, special_titles, amodifiers, ndescriptors = load_lists()\n\nif __name__ == \"__main__\":\n    infile, outfile = sys.argv[1:]\n\n    tree = ET.parse(infile)\n    if not tree.getroot().tail:\n        tree.getroot().tail = \"\\n\"\n    for paper in tree.getroot().findall(\".//paper\"):\n        for title in paper.xpath(\"./title|./booktitle\"):\n            protect(title)\n    tree.write(outfile, encoding=\"UTF-8\", xml_declaration=True)\n", "path": "bin/fixedcase/protect.py"}]}