Trim long patterns rather than clearing them.

Fixes #5973.

2 files changed, 8 insertions, 5 deletions

diff --git a/qutebrowser/completion/models/listcategory.py b/qutebrowser/completion/models/listcategory.py
index 307e1ec33..fbe742ddb 100644
--- a/qutebrowser/completion/models/listcategory.py
+++ b/qutebrowser/completion/models/listcategory.py
@@ -59,13 +59,13 @@ class ListCategory(QSortFilterProxyModel):
         Args:
             val: The value to set.
         """
+        if len(val) > 5000:  # avoid crash on huge search terms (#5973)
+            log.completion.warning(f"Trimming {len(val)}-char pattern to 5000")
+            val = val[:5000]
         self._pattern = val
         val = re.sub(r' +', r' ', val)  # See #1919
         val = re.escape(val)
         val = val.replace(r'\ ', '.*')
-        if len(val) > 5000:  # avoid crash on huge search terms (#5973)
-            log.completion.warning(f"Pattern too long ({len(val)})")
-            val = "^$"
         rx = QRegularExpression(val, QRegularExpression.CaseInsensitiveOption)
         qtutils.ensure_valid(rx)
         self.setFilterRegularExpression(rx)
diff --git a/tests/unit/completion/test_listcategory.py b/tests/unit/completion/test_listcategory.py
index 3a4fa895d..b00ab595e 100644
--- a/tests/unit/completion/test_listcategory.py
+++ b/tests/unit/completion/test_listcategory.py
@@ -60,7 +60,10 @@ def test_set_pattern(pattern, before, after, after_nosort, model_validator):
     model_validator.validate(after_nosort)
 
 
-def test_long_pattern(caplog):
+def test_long_pattern(caplog, model_validator):
     """Validate that a huge pattern doesn't crash (#5973)."""
     with caplog.at_level(logging.WARNING):
-        listcategory.ListCategory('Foo', []).set_pattern('a' * 50000)
+        cat = listcategory.ListCategory('Foo', [('a' * 5000, '')])
+        model_validator.set_model(cat)
+        cat.set_pattern('a' * 50000)
+        model_validator.validate([('a' * 5000, '')])