ui: make readsections() abort when configuration cannot be read.

mercurial/ui.py

@@ -170,7 +170,15 b' class ui(object):'
 
         cdata = util.configparser()
         try:
-            cdata.read(filename)
+            try:
+                fp = open(filename)
+            except IOError, inst:
+                raise util.Abort(_("unable to open %s: %s") % (filename, 
+                                   getattr(inst, "strerror", inst)))
+            try:
+                cdata.readfp(fp, filename)
+            finally:
+                fp.close()
         except ConfigParser.ParsingError, inst:
             raise util.Abort(_("failed to parse %s\n%s") % (filename,
                                                             inst))

tests/test-acl.out

@@ -470,12 +470,11 b' adding foo/file.txt revisions'
 adding quux/file.py revisions
 added 3 changesets with 3 changes to 3 files
 calling hook pretxnchangegroup.acl: hgext.acl.hook
-acl: acl.allow enabled, 1 entries for user barney
-acl: acl.deny enabled, 0 entries for user barney
-acl: allowing changeset ef1ea85a6374
-acl: allowing changeset f9cafe1212c8
-acl: allowing changeset 911600dab2ae
-rolling back last transaction
+error: pretxnchangegroup.acl hook failed: unable to open ../acl.config: No such file or directory
+abort: unable to open ../acl.config: No such file or directory
+transaction abort!
+rollback completed
+no rollback information available
 0:6675d58eff77
 
 betty is allowed inside foo/ by a acl.config file

tests/test-notify

@@ -48,6 +48,12 b' template = Subject: {desc|firstline|stri'
 baseurl = http://test/
 EOF
 
+echo % fail for config file is missing
+hg --cwd b rollback
+hg --cwd b pull ../a 2>&1 | grep 'unable to open.*\.notify\.conf' > /dev/null && echo pull failed
+
+touch "$HGTMP/.notify.conf"
+
 echo % pull
 hg --cwd b rollback
 hg --traceback --cwd b pull ../a 2>&1 | sed -e 's/\(Message-Id:\).*/\1/' \

tests/test-notify.out

@@ -34,6 +34,9 b' diff -r cb9a9f314b8b -r 0647d048b600 a'
  a
 +a
 (run 'hg update' to get a working copy)
+% fail for config file is missing
+rolling back last transaction
+pull failed
 % pull
 rolling back last transaction
 pulling from ../a