wmlxgettext: Improve parser resiliency for malformed files (#7625)

* wmlxgettext: Improve parser resiliency for malformed files

- WML files with no translatable strings will no longer
crash the script on unbalanced tags (but translatable will).
- .cfg files belonging to man(1) will no longer crash the script.

* Remove stray quotes from textdomain declarations

These are not recognized by the wmlxgettext parser.

data/gui/widget/label_achievement_title.cfg

@@ -1,4 +1,4 @@
-#textdomain "wesnoth-lib"
+#textdomain wesnoth-lib
 
 #define _GUI_ACHIEVEMENT_TITLE_FONT_COLOR STATE
 "(

data/modifications/pick_advance/gui/pick_advance.cfg

@@ -1,4 +1,4 @@
-#textdomain "wesnoth"
+#textdomain wesnoth
 
 #define SINGLE_UNIT_CODE
 -1#enddef

data/tools/pywmlx/nodemanip.py

@@ -9,12 +9,20 @@ fileref = None
 fileno = None
 nodes = None
 onDefineMacro = False
+unbalanced_wml = None
 
 
 
 def _closenode_update_dict(podict):
+    global unbalanced_wml
     if nodes[-1].sentences is not None:
         for i in nodes[-1].sentences:
+            if unbalanced_wml is not None:
+                # At this point we know that the file has translatable strings.
+                # If it has unbalanced tags, raise an exception. Note that would the error
+                # be ignored, then wrong context info would be attached to these sentences,
+                # or to an undetermined future sentence.
+                wmlerr(*unbalanced_wml)
             posentence = podict.get(i.sentence)
             if posentence is None:
                 podict[i.sentence] = (
@@ -40,6 +48,7 @@ def newfile(file_ref, file_no):
 
 
 def closefile(mydict, lineno):
+    global unbalanced_wml
     if nodes is not None:
         if len(nodes) > 1:
             err_message = ("End of WML file reached, but some tags were " +
@@ -47,9 +56,12 @@ def closefile(mydict, lineno):
                             "(nearest unclosed tag is: " +
                             nodes[-1].tagname + ")" )
             finfo = fileref + ":" + str(lineno)
-            wmlerr(finfo, err_message)
-        else:
-            _closenode_update_dict(mydict)
+            wmlwarn(finfo, err_message)
+            while len(nodes) > 1:
+                closenode("", mydict, lineno)
+        _closenode_update_dict(mydict)
+    unbalanced_wml = None
+
 
 
 def newnode(tagname):
@@ -71,11 +83,13 @@ def closenode(closetag, mydict, lineno):
     global fileref
     global fileno
     global nodes
+    global unbalanced_wml
     if nodes is None:
         err_message = ("unexpected closing tag '" +
                             closetag + "' outside any scope.")
         finfo = fileref + ":" + str(lineno)
-        wmlerr(finfo, err_message)
+        unbalanced_wml = (finfo, err_message)
+        wmlwarn(*unbalanced_wml)
     else:
         # node to close is the LAST element in self.nodes list
         mytag = nodes[-1].tagname
@@ -85,15 +99,19 @@ def closenode(closetag, mydict, lineno):
         if mynode.tagname == "":
             err_message = ("unexpected closing tag '" +
                             closetag + "' outside any scope.")
-            wmlerr(finfo, err_message)
+            unbalanced_wml = (finfo, err_message)
+            wmlwarn(*unbalanced_wml)
         else:
             if closetag != expected_closetag:
                 err_message = ("expected closing tag '" +
                                 expected_closetag + "' but '" +
                                 closetag + "' found.")
-                wmlerr(finfo, err_message)
+                unbalanced_wml = (finfo, err_message)
+                wmlwarn(*unbalanced_wml)
         _closenode_update_dict(mydict)
         nodes.pop()
+        if len(nodes) == 0:
+            nodes = None
 
 
 def addNodeSentence(sentence, *, ismultiline, lineno, lineno_sub,