[IMP] Cleanup and refactoring of exception handling

Unify and refactor exception handling in framework and addons.

The generic `except_osv` is now deprecated, and replaced by more specialized exception subtypes:
 - `UserError` (renamed from Warning, as it conflicts with the built-in `Warning`) raised when a non-technical error occurs during a business operation. It could be a missing information in the data provided by the user, or a misconfiguration.
 - `AccessError`: raised when any operation is denied because the user conducting it does not have the required access rights.
 - `AccessDenied`: raised when an operation that requires authenticated access is attempted via an unauthenticated request.
 - `MissingError`: raised when an operation is attempted on a record that does not exist.
 - `ValidationError`: raised when an operation violates a SQL or Python constraint.
 - All other exceptions are internal errors due to a system problem or bug, and raised untouched to the client-side, which should display a traceback.

All exceptions take a single message argument.

The `test_exceptions` module has been updated to showcase both new and old (deprecated) exceptions.

A great many old `except_osv` had a useless title with "Error!" or "Warning", those have been removed, as this is handled by the client-side widget that displays the messages.

This commit introduces a more consistent policy for logging errors and warnings:
 - All messages that do not require administrator attention should be logged at INFO level or lower. This includes all errors that are notified to the user in a friendly manner, even for access right problems or validation errors during business operations.
 - All messages that indicate a likely misconfiguration or malicious use by the users should be logged at WARNING level, as they typically require administrator attention.
 - All other unhandled internal errors cannot typically be handled by the user and should be logged at ERROR or higher level, as they require immediate administrator attention.

1 files changed, 4 insertions, 3 deletions

diff --git a/addons/project_issue/project_issue.py b/addons/project_issue/project_issue.py
index 0dc3e0a5925..8898272b744 100644
--- a/addons/project_issue/project_issue.py
+++ b/addons/project_issue/project_issue.py
@@ -31,6 +31,7 @@ from openerp.osv import fields, osv, orm
 from openerp.tools import DEFAULT_SERVER_DATETIME_FORMAT
 from openerp.tools import html2plaintext
 from openerp.tools.translate import _
+from openerp.exceptions import UserError, AccessError
 
 
 class project_issue_version(osv.Model):
@@ -408,7 +409,7 @@ class project_issue(osv.Model):
             data = {}
             esc_proj = issue.project_id.project_escalation_id
             if not esc_proj:
-                raise osv.except_osv(_('Warning!'), _('You cannot escalate this issue.\nThe relevant Project has not configured the Escalation Project!'))
+                raise UserError(_('You cannot escalate this issue.\nThe relevant Project has not configured the Escalation Project!'))
 
             data['project_id'] = esc_proj.id
             if esc_proj.user_id:
@@ -438,7 +439,7 @@ class project_issue(osv.Model):
                     self._message_add_suggested_recipient(cr, uid, recipients, issue, partner=issue.partner_id, reason=_('Customer'))
                 elif issue.email_from:
                     self._message_add_suggested_recipient(cr, uid, recipients, issue, email=issue.email_from, reason=_('Customer Email'))
-        except (osv.except_osv, orm.except_orm):  # no read access rights -> just ignore suggested recipients because this imply modifying followers
+        except AccessError:  # no read access rights -> just ignore suggested recipients because this imply modifying followers
             pass
         return recipients
 
@@ -544,7 +545,7 @@ class account_analytic_account(osv.Model):
         proj_ids = self.pool['project.project'].search(cr, uid, [('analytic_account_id', 'in', ids)])
         has_issues = self.pool['project.issue'].search(cr, uid, [('project_id', 'in', proj_ids)], count=True, context=context)
         if has_issues:
-            raise osv.except_osv(_('Warning!'), _('Please remove existing issues in the project linked to the accounts you want to delete.'))
+            raise UserError(_('Please remove existing issues in the project linked to the accounts you want to delete.'))
         return super(account_analytic_account, self).unlink(cr, uid, ids, context=context)