Merged from trunk -r12608:12619

   Merged from trunk -r12608:12619

   | 12609   | Automatically export QA_PRESTRIPPED if it's set. Thanks to   |
   | zmedico | Raúl Porcel <armin76@g.o> for reporting.                    |

   | 12610   | For the --buildpkgonly digraph.hasallzeros() check, remove   |
   | zmedico | "nomerge" nodes from the graph. This makes it unnecessary to |
   |         | tweak the dependency priority for onlydeps packages inside   |
   |         | depgraph._add_pkg_dep().                                     |

   | 12611   | In depgraph._serialize_tasks(), when appropriate, execute    |
   | zmedico | uninstall tasks sooner. This solves some cases of bug        |
   |         | #256870 since there is a smaller window of time for some     |
   |         | other failure to cause the uninstall to get discarded.       |

   | 12612   | Bug #250020 - When calculating merge order, try to ensure    |
   | zmedico | that packages listed in DEPEND are updated before whenever   |
   |         | possible (even though the DEPEND may already be satisfied by |
   |         | an installed instance). The changes to the merge order       |
   |         | algorithm should also account for many common cases of bug   |
   |         | #199856, but does not necessarily solve all cases. Whenever  |
   |         | possible, the new algorithm avoids dropping dependencies     |
   |         | that are satisfied by installed packages. Such dependencies  |
   |         | are only dropped in a couple of cases: * when solving        |
   |         | circular dependencies * when promoting packages to in the    |
   |         | merge list (either due an unsatisfied PDEPEND or a portage   |
   |         | upgrade)                                                     |

   | 12613   | Fix merge order calculation so that the circular runtime     |
   | zmedico | path isn't entered when it's possible to select a node that  |
   |         | only has unsatisfied PDEPEND. This reverts an unintended     |
   |         | change from the patch for bug #250020, and solves a problem  |
   |         | with libperl being merged after perl when building stage 1.  |

   | 12614   | Fix isvalidatom to properly identify an invalid atom such as |
   | zmedico | 'dev-java/nanoxml*'. Thanks to Vlastimil Babka <caster@g.o>  |
   |         | for reporting.                                               |

   | 12615   | Fix isvalidatom() logic from previous commit to avoid false  |
   | zmedico | positives.                                                   |

   | 12616   | Fix more false positives in isvalidatom() from previous      |
   | zmedico | commits.                                                     |

   | 12617   | Add a test case for the new case which is detected by        |
   | zmedico | isvalidatom().                                               |

   | 12618   | In dyn_package(), show a more informative die message if an  |
   | zmedico | error occurs when creating the tarball.                      |

   | 12619   | Fix broken references to DepPriority attributes.             |
   | zmedico |                                                              |

svn path=/main/branches/prefix/; revision=12650