Merge remote-tracking branch 'origin/master' into 5.9

* Test/D02glob.ztst:
  On the "unreadable directories can be globbed (users/24619, users/24626)"
  test, resolve conflicts by removing the Cygwin-only skip that has been added
  in master, since the test is passing on this branch.  This effectively reverts
  workers/45492.  See discussion starting in workers/45504.

* origin/master:
  unposted: Remove 'sgi', as that OpenBSD port has been discontinued.
  45509: fix typos in B01cd.ztst
  45490 (+45495 and a test): refactor rlimits.c
  github #49: Fix typo: longson should be loongson
  users/24710: Fix job control problem with sudo.
  45492: skip test added by users/24633 on Cygwin
  45488: COMP_WORDS for bash need "$@"-style quoting
  45487: Missing mod_export declarations for AIX
  45447: Complete vcs_info_hookadd and vcs_info_hookdel. Expose _vcs_info_hooks as a top-level helper function.
  45463: test: kill: Document why we use SIGURG
  45453: builtins: kill: Do not signal current process group when pid is empty
  45452: builtins: kill: Add `kill ''` regression test with explicit sigspec
  45451: builtins: kill: Add basic test suite
  github #48/0002: vcs_info git: properly detect bare repositories
  github #48/0001: vcs_info git: avoid warnings in bare repositories
  unposted: Post-release version bump
  unposted: Release 5.8
  CVE-2019-20044: Update change log for preceding commits
  Update NEWS/README
  Add unsetopt/PRIVILEGED tests
  Clean up error-message white space
  Improve PRIVILEGED fixes (again)
  Improve PRIVILEGED fixes
  Drop privileges securely
  unposted: V01zmodload: Fix failing test from workers/45385
  45423: _su: Improve arg handling, shell look-ups
  unposted: _zip: Recognise '--'
  45385: Add a test for 'zmodload -Fa' preemptively disabling ("blacklisting"?) features.
  unposted: Test release: 5.7.1-test-3
  zsh/system: Fix infinite loop in sysread
  _diff_options: Restore -w completion lost in workers/43351
  unposted: Fix ChangeLog typo.
  45368: Add tests for workers/45367's issue about double slashes in 'cd -P' and /home/daniel/in/zsh.
  45373: Fix ERR_EXIT bug in else branch of if.
  45372: Record a symlink loop bug involving :P
  45365: _git: Fix __git_recent_branches for the case when a commit has an empty message
  45343: Queue signals around arithmetic evaluations
  45344: Document where third-party completion functions should be installed.
  45345: internal: ztst.vim: Fix highlighting of zsh comments in test payload
  unposted: internal: Add some comments and fix indentation.  No functional change.
  45340: internal: Document the difference between paramtab and realparamtab.
  45332: _git: add completion for git-version
  _brace_parameter: add missing \

Conflicts:
	ChangeLog
	Test/D02glob.ztst
	Test/V01zmodload.ztst

1 files changed, 77 insertions, 17 deletions

diff --git a/Src/zsh_system.h b/Src/zsh_system.h
index 85e198f2e..161b073b4 100644
--- a/Src/zsh_system.h
+++ b/Src/zsh_system.h
@@ -468,30 +468,90 @@ struct timespec {
 # define setpgrp setpgid
 #endif
 
-/* can we set the user/group id of a process */
+/* compatibility wrappers */
 
-#ifndef HAVE_SETUID
+/* Our strategy is as follows:
+ *
+ * - Ensure that either setre[ug]id() or set{e,}[ug]id() is available.
+ * - If setres[ug]id() are missing, provide them in terms of either
+ *   setre[ug]id() or set{e,}[ug]id(), whichever is available.
+ * - Provide replacement setre[ug]id() or set{e,}[ug]id() if they are not
+ *   available natively.
+ *
+ * There isn't a circular dependency because, right off the bat, we check that
+ * there's an end condition, and #error out otherwise.
+ */
+#if !defined(HAVE_SETREUID) && !(defined(HAVE_SETEUID) && defined(HAVE_SETUID))
+  /*
+   * If you run into this error, you have two options:
+   * - Teach zsh how to do the equivalent of setreuid() on your system
+   * - Remove support for PRIVILEGED option, and then remove the #error.
+   */
+# error "Don't know how to change UID"
+#endif
+#if !defined(HAVE_SETREGID) && !(defined(HAVE_SETEGID) && defined(HAVE_SETGID))
+  /* See above comment. */
+# error "Don't know how to change GID"
+#endif
+
+/* Provide setresuid(). */
+#ifndef HAVE_SETRESUID
+int	setresuid(uid_t, uid_t, uid_t);
+# define HAVE_SETRESUID
+# define ZSH_IMPLEMENT_SETRESUID
 # ifdef HAVE_SETREUID
-#  define setuid(X) setreuid(X,X)
-#  define setgid(X) setregid(X,X)
-#  define HAVE_SETUID
+#  define ZSH_HAVE_NATIVE_SETREUID
 # endif
 #endif
 
-/* can we set the effective user/group id of a process */
+/* Provide setresgid(). */
+#ifndef HAVE_SETRESGID
+int	setresgid(gid_t, gid_t, gid_t);
+# define HAVE_SETRESGID
+# define ZSH_IMPLEMENT_SETRESGID
+# ifdef HAVE_SETREGID
+#  define ZSH_HAVE_NATIVE_SETREGID
+# endif
+#endif
 
+/* Provide setreuid(). */
+#ifndef HAVE_SETREUID
+# define setreuid(X, Y) setresuid((X), (Y), -1)
+# define HAVE_SETREUID
+#endif
+
+/* Provide setregid(). */
+#ifndef HAVE_SETREGID
+# define setregid(X, Y) setresgid((X), (Y), -1)
+# define HAVE_SETREGID
+#endif
+
+/* Provide setuid(). */
+/* ### TODO: Either remove this (this function has been standard since 1985),
+ * ###       or rewrite this without multiply-evaluating the argument */
+#ifndef HAVE_SETUID
+# define setuid(X) setreuid((X), (X))
+# define HAVE_SETUID
+#endif
+
+/* Provide setgid(). */
+#ifndef HAVE_SETGID
+/* ### TODO: Either remove this (this function has been standard since 1985),
+ * ###       or rewrite this without multiply-evaluating the argument */
+#  define setgid(X) setregid((X), (X))
+#  define HAVE_SETGID
+#endif
+
+/* Provide seteuid(). */
 #ifndef HAVE_SETEUID
-# ifdef HAVE_SETREUID
-#  define seteuid(X) setreuid(-1,X)
-#  define setegid(X) setregid(-1,X)
-#  define HAVE_SETEUID
-# else
-#  ifdef HAVE_SETRESUID
-#   define seteuid(X) setresuid(-1,X,-1)
-#   define setegid(X) setresgid(-1,X,-1)
-#   define HAVE_SETEUID
-#  endif
-# endif
+# define seteuid(X) setreuid(-1, (X))
+# define HAVE_SETEUID
+#endif
+
+/* Provide setegid(). */
+#ifndef HAVE_SETEGID
+# define setegid(X) setregid(-1, (X))
+# define HAVE_SETEGID
 #endif
 
 #ifdef HAVE_SYS_RESOURCE_H