[FIX] util/fields : update field in context of custom search view

This commit aims to make views compatible which are generated when a
search filter is created using studio, view looks like
<data>
  <xpath expr="xyz" position="after">
    <filter name="filter1"  context="{'group_by': 'renamed field'}"/>
    <filter name="filter2"  context="{'group_by': 'removed field'}"/>
  </xpath>
</data>

Currently after upgrade this view will be disabled because we are not updating
the field in this view.

After this fix

view:
<data>
  <xpath expr="xyz" position="after">
    <filter name="filter1"  context="{'group_by': 'New Name'}"/>
    <filter name="filter2"  context="{}"/>
  </xpath>
</data>

src/util/fields.py

@@ -5,6 +5,7 @@
 import re
 import warnings
 
+import lxml
 import psycopg2
 
 try:
@@ -18,6 +19,12 @@
     from openerp.tools.misc import mute_logger
     from openerp.tools.safe_eval import safe_eval
 
+try:
+    from contextlib import suppress
+except ImportError:
+    # python2 code, use the openerp vendor
+    from openerp.tools.misc import ignore as suppress
+
 try:
     from odoo.tools.sql import make_index_name
 except ImportError:
@@ -45,6 +52,7 @@ def make_index_name(table_name, column_name):
     savepoint,
     table_exists,
 )
+from .records import edit_view
 from .report import add_to_migration_reports, get_anchor_link_to_record
 
 # python3 shims
@@ -54,6 +62,10 @@ def make_index_name(table_name, column_name):
     basestring = unicode = str
 
 
+class _Skip(Exception):
+    pass
+
+
 _logger = logging.getLogger(__name__)
 IMD_FIELD_PATTERN = "field_%s__%s" if version_gte("saas~11.2") else "field_%s_%s"
 
@@ -153,6 +165,9 @@ def clean_context(context):
         if changed:
             add_to_migration_reports(("ir.filters", id_, name), "Filters/Dashboards")
 
+    # clean filter's of custom search view
+    update_custom_filter(cr, fieldname, model)
+
     def adapter(leaf, is_or, negated):
         # replace by TRUE_LEAF, unless negated or in a OR operation but not negated
         if is_or ^ negated:
@@ -998,6 +1013,8 @@ def adapt_dict(d):
             # skip all inherit, they will be handled by the resursive call
             adapt_domains(cr, model, old, new, adapter=domain_adapter, skip_inherit="*", force_adapt=True)
             adapt_related(cr, model, old, new, skip_inherit="*")
+            # clean filter's of custom search view
+            update_custom_filter(cr, old, model, new)
 
         inherited_models = tuple(
             inh.model for model in only_models for inh in for_each_inherit(cr, model, skip_inherit)
@@ -1121,3 +1138,48 @@ def update_server_actions_fields(cr, src_model, dst_model=None, fields_mapping=N
         ) % {"src_model": src_model, "dst_model": dst_model, "actions": ", ".join(action_names)}
 
         add_to_migration_reports(message=msg, category="Server Actions")
+
+
+def update_custom_filter(cr, old, model, new=None):
+    arch_db = (
+        get_value_or_en_translation(cr, "ir_ui_view", "arch_db")
+        if column_exists(cr, "ir_ui_view", "arch_db")
+        else "arch"
+    )
+    match_old = r"\y{}\y".format(re.escape(old))
+    cr.execute(
+        """
+            SELECT id
+              FROM ir_ui_view
+             WHERE {} ~ %s
+               AND type = 'search'
+               AND model = %s
+               AND active = 't'
+        """.format(
+            arch_db
+        ),
+        [match_old, model],
+    )
+    for view_id in cr.fetchall():
+        try:
+            with suppress(_Skip), edit_view(cr, view_id=view_id, active=None) as view:
+                for elem in view.xpath("//filter[contains(@context, '{0}')]".format(old)):
+                    context = elem.attrib["context"]
+                    context = safe_eval(context or "{}", SelfPrintEvalContext(), nocopy=True)
+                    if "group_by" in context and context["group_by"] == old:
+                        if new:
+                            context["group_by"] = new
+                        else:
+                            context.pop("group_by")
+                            _logger.info(
+                                "Field %s was removed during the upgrade, context has been updated from filter %s to avoid disabling of custom view",
+                                old,
+                                elem.attrib["name"],
+                            )
+                        elem.attrib["context"] = unicode(context)
+        except lxml.etree.XMLSyntaxError as e:
+            if e.msg.startswith("Opening and ending tag mismatch"):
+                # this view is already wrong, we don't change it
+                _logger.warning("Skipping custom filter adaptaiton for invalid view (id=%s):\n%s", view_id, e.msg)
+                continue
+            raise