Fix etags for Ruby module definitions with ::

Problem: In Ruby we can define a nested module/class the safe
way (in the sense, if the parent module does not exist, it will
define it:

  module M
    module N
    end
  end

If M already exists, we can also write:

  module M::N; end

With the later notation, the tag generated by etags will be M::N.
When browsing the code, using xref-find-definitions when the point
is on N, will not be able to find the definition of N because the
implicit tag name is M::N.

This is the same problem with nested classes or even some rare
allowed definitions like explicitely defining a module/class from
the global namespace:

  class ::A; end

Solution: We need to give an explicit tag name.  To achieve this,
on module/class definition we truncate the name to the last found
column.
* lib-src/etags.c (Ruby_functions): Support "::" in module
definitions.
* test/manual/etags/README: Update instructions.
* test/manual/etags/ruby-src/test1.ru: Add identifiers with "::".
* test/manual/etags/CTAGS.good:
* test/manual/etags/CTAGS.good_crlf:
* test/manual/etags/CTAGS.good_update:
* test/manual/etags/ETAGS.good_1:
* test/manual/etags/ETAGS.good_2:
* test/manual/etags/ETAGS.good_3:
* test/manual/etags/ETAGS.good_4:
* test/manual/etags/ETAGS.good_5:
* test/manual/etags/ETAGS.good_6:
* test/manual/etags/ETAGS.good_7: Adapt expected results to the
change.  (Bug#77421)

Copyright-paperwork-exempt: yes

1 files changed, 4 insertions, 1 deletions

diff --git a/lib-src/etags.c b/lib-src/etags.c
index d511bc39588..6dde9c42e13 100644
--- a/lib-src/etags.c
+++ b/lib-src/etags.c
@@ -5069,7 +5069,10 @@ Ruby_functions (FILE *inf)
          /* Ruby method names can end in a '='.  Also, operator overloading can
             define operators whose names include '='.  */
           while (!notinname (*cp) || *cp == '=')
-            cp++;
+            {
+              cp++;
+              if (*(cp - 1) == ':') name = cp;
+            }
 
           /* Remove "self." from the method name.  */
           if (cp - name > self_size1