Re: Package choosing algorithm ...

[Houder <houder at xs4all dot nl>]

Title: Re: Package choosing agorithm ...

Hi Corinna,

(Of course I am formally addressing the project leader, but Achim, Jon, 
Yaakov,
 others? are welcome to correct me if I am wrong below).

D w/o I = Download without Install
I f LD  = Install from Local Directory

As a reminder: I reported that a new test release of Cygwin is NOT 
offered
for install (having installed the previous test release) in my case.

    https://cygwin.com/ml/cygwin/2016-03/msg00425.html

Relevant in my case is:

 - I am not using a local mirror ...
     - but a "partially populated Local Directory"
 - I do not invoke setup.exe with the -m option
 - my local directory does not have the current release of Cygwin

As you replied "it works for me" and "not using the -m option should not
make a difference", I decided to study the source code of setup.exe.

As I had never seen the source code of setup before, I started my study 
where
you had "left off" modifying (about a year ago).

Subsequently, I reported back to the list, announcing that I found the 
bug,
but was not sure I had.

   https://cygwin.com/ml/cygwin/2016-03/msg00480.html

I was wrong.

My patch did work, but for the wrong reasons.

So does your modification of packagemeta::trustp ...

Here is another attempt of mine (attempt? I seriously doubt whether 
there is
someone which fully understands the source code in all its details ...)

You will find 2 patch files attached. These patch files modify 
(correct):

 1. packagemeta::ScanDownLoadedFiles and
 2. packagemeta::trustp

(yes, I do realize, that this correction to setup, is NOT important 
enough to
 most of you - using a local mirror and all that; consequently, do 
whatever you
 like with my post - I am merely providing info to the list).

My argument for the correction is as follows:

 - packagedb::packages, a class variable, is the "package database" that 
is
   used by setup.
 - basically, it is a list of pairs (mapping between the packagename and 
its
   entry in setup.ini) (one where installed.db has been "integrated").
 - formally:
    - typedef std::map <std::string, packagemeta *> packagecollection;
    - static packagecollection packages;
 - packagemeta is the type that describes a "package entry" from 
setup.ini
 - an object of type packagemeta does not only describe the previous, 
current
   and experimental (if applicable) lines from a package entry in 
setup.ini,
   it also describes the installed version of a package, as if 
installed.db is
   part of setup.ini.
--
 - bottom-line: the prev, curr, exp and installed data member of 
packagemeta
   are "static": these data members represent the info from setup.ini 
(and
   installed.db) and they should never be "nullified".
 - yet, that is exactly what happens in 
metapackage::ScanDownLoadedFiles.
--
 - packagemeta ALSO has a "not so static" data member, called versions; 
like
   packages, the contents of versions is "variable"
    - versions, a set of type packageversion, contains the versions of 
the
      package that are available (the source code speaks about 
"accessible")
    - available (in my simplistic view) means whether or not the tarball 
is
      present in the (local) repo
    - unfortunately, though versions specifies which versions are 
available,
      it does not tell us whether the previous, current or experimental
      version of a package is available or not
--
 - bottom-line: version numbers can be compared if that info is present 
in
   setup.ini; however, although the info may be present, it does not 
tell us
   that the associated tarball is available (neither does versions).
 - consequently, metapackage:trustp does not only have to verify that
   setup.ini has the required info, it also has to verify that the 
tarball
   is available, before it can give the "go-ahead".

Lastly: No, I have not tested (been able) my modification for each 
possible
configuration out there (for instance, I do not install source 
tarballs).

Regards,
Henri

=====

diff --git a/package_meta.cc b/package_meta.cc
index 34ff78c..ff787a8 100644
--- a/package_meta.cc
+++ b/../src2/package_meta.cc
@@ -683,15 +683,18 @@ packagemeta::ScanDownloadedFiles (bool mirror_mode)
 	  /* For local installs, if there is no src and no bin, the version
 	   * is unavailable
 	   */
-	  if (!i->accessible () && !pkgsrcver.accessible ()
-	      && *i != pkg.installed)
+	  if (*i != pkg.installed
+	      && !i->accessible () && !pkgsrcver.accessible () )
 	    {
+// Henri: innihilate the info that has been collected from setup.ini? DO NOT!
+	      #if 0
 	      if (pkg.prev == *i)
 		pkg.prev = packageversion ();
 	      if (pkg.curr == *i)
 		pkg.curr = packageversion ();
 	      if (pkg.exp == *i)
 		pkg.exp = packageversion ();
+	      #endif
 	      pkg.versions.erase (i++);
 	      /* For now, leave the source version alone */
 	    }

diff --git a/package_meta.h b/package_meta.h
index b24d4fc..3d2b775 100644
--- a/package_meta.h
+++ b/../src2/package_meta.h
@@ -105,12 +105,14 @@ public:
     if (_default && curr && installed
 	&& packageversion::compareVersions (curr, installed) < 0)
       {
-	if (exp && packageversion::compareVersions (installed, exp) < 0)
+// Henri: no, no, no ... first check whether the associated tarball is in the repo or not!
+	if (exp.accessible() && exp && packageversion::compareVersions (installed, exp) < 0)
 	  return exp;
 	return installed;
       }
     /* Otherwise, if a "curr" version exists, return "curr". */
-    if (curr)
+// Henri: no, no, no ... first check whether the associated tarball is in the repo or not!
+    if (curr.accessible() && curr)
       return curr;
     /* Otherwise return the installed version. */
     return installed;

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