Rework vms/vms.c:Perl_flex_stat_int() to avoid underscore ambiguity.

An apparently long-standing bug in the home-grown stat() wrapper
was exposed by b8ab4b0, which added the t/test_pl directory. On
VMS, file test operations using the Perl_flex_stat_int() function
would confuse t/test.pl with t/test_pl because dots are the directory
delimiter and not traditionally allowed in directory names, so when
doing a stat() of t/test.pl it would convert the dot to an underscore
and succeed because that directory now exists.  All tests using
t/test.pl would then fail.

The background is that traditionally, the CRTL stat() could not deal
with directory specifications in native format, so for example,
dev:[dir.dir2] had to be converted to dev:[dir]dir2.DIR for various
operations, including the stat() call, to succeed.  This is now the
exception; it's still necessary for rmdir(), but not for stat(), at
least not on OpenVMS VAX v7.3, OpenVMS Alpha v7.3-2, OpenVMS Alpha
v8.3, and OpenVMS I64 v8.4, i.e., anything released in the last
eight years.  A so-called "fileified" directory spec did not cause
problems on its own, but if converted to native syntax first, the
dot would get replace with the now-ambiguous underscore.

The balance was tipped in 312ac60b381, where the fatal conversion
to a native path was added.  The best path forward seems to be to
do less and allow the CRTL stat() or lstat() to do their thing
unimpeded, which in most cases they do just fine.  This has the
added benefit of optimizing for files instead of directories and
saving some unnecessary filename conversions and filename buffer
allocations.  More refactorings are likely desireable.

There is one new test failure in dist/ExtUtils-Manifest/t/Manifest.t
having to do with a filename containing a space, but this seems
preferable to the hundreds of test failures before this patch.  That
indicates, however, that there is more work to do.

1 files changed, 51 insertions, 50 deletions

diff --git a/vms/vms.c b/vms/vms.c
index f90a8ab9d9..425a63dadf 100644
--- a/vms/vms.c
+++ b/vms/vms.c
@@ -12623,8 +12623,8 @@ Perl_flex_fstat(pTHX_ int fd, Stat_t *statbufp)
 static int
 Perl_flex_stat_int(pTHX_ const char *fspec, Stat_t *statbufp, int lstat_flag)
 {
-    char *fileified;
-    char *temp_fspec;
+    char *temp_fspec = NULL;
+    char *fileified = NULL;
     const char *save_spec;
     char *ret_spec;
     int retval = -1;
@@ -12649,58 +12649,37 @@ Perl_flex_stat_int(pTHX_ const char *fspec, Stat_t *statbufp, int lstat_flag)
       }
     }
 
-    /* Try for a directory name first.  If fspec contains a filename without
+    SAVE_ERRNO;
+
+#if __CRTL_VER >= 80200000 && !defined(__VAX)
+  /*
+   * If we are in POSIX filespec mode, accept the filename as is.
+   */
+  if (decc_posix_compliant_pathnames == 0) {
+#endif
+
+    /* Try for a simple stat first.  If fspec contains a filename without
      * a type (e.g. sea:[wine.dark]water), and both sea:[wine.dark]water.dir
-     * and sea:[wine.dark]water. exist, we prefer the directory here.
+     * and sea:[wine.dark]water. exist, the CRTL prefers the directory here.
      * Similarly, sea:[wine.dark] returns the result for sea:[wine]dark.dir,
      * not sea:[wine.dark]., if the latter exists.  If the intended target is
      * the file with null type, specify this by calling flex_stat() with
      * a '.' at the end of fspec.
-     *
-     * If we are in Posix filespec mode, accept the filename as is.
      */
 
+    if (lstat_flag == 0)
+        retval = stat(fspec, &statbufp->crtl_stat);
+    else
+        retval = lstat(fspec, &statbufp->crtl_stat);
 
-    fileified = PerlMem_malloc(VMS_MAXRSS);
-    if (fileified == NULL)
-        _ckvmssts_noperl(SS$_INSFMEM);
-     
-    temp_fspec = PerlMem_malloc(VMS_MAXRSS);
-    if (temp_fspec == NULL)
-        _ckvmssts_noperl(SS$_INSFMEM);
-
-    my_strlcpy(temp_fspec, fspec, VMS_MAXRSS);
-
-    SAVE_ERRNO;
-
-#if __CRTL_VER >= 80200000 && !defined(__VAX)
-  if (decc_posix_compliant_pathnames == 0) {
-#endif
-
-    /* We may be able to optimize this, but in order for fileify_dirspec to
-     * always return a usuable answer, we have to call vmspath first to
-     * make sure that it is in VMS directory format, as stat/lstat on 8.3
-     * can not handle directories in unix format that it does not have read
-     * access to.  Vmspath handles the case where a bare name which could be
-     * a logical name gets passed.
-     */ 
-    ret_spec = int_tovmspath(fspec, temp_fspec, NULL);
-    if (ret_spec != NULL) {
-        ret_spec = int_fileify_dirspec(temp_fspec, fileified, NULL); 
-        if (ret_spec != NULL) {
-            if (lstat_flag == 0)
-                retval = stat(fileified, &statbufp->crtl_stat);
-            else
-                retval = lstat(fileified, &statbufp->crtl_stat);
-            save_spec = fileified;
-        }
-    }
-
+    save_spec = fspec;
     if (retval && vms_bug_stat_filename) {
 
-        /* We should try again as a vmsified file specification */
-        /* However Perl traditionally has not done this, which  */
-        /* causes problems with existing tests */
+        temp_fspec = PerlMem_malloc(VMS_MAXRSS);
+        if (temp_fspec == NULL)
+            _ckvmssts_noperl(SS$_INSFMEM);
+
+        /* We should try again as a vmsified file specification. */
 
         ret_spec = int_tovmsspec(fspec, temp_fspec, 0, NULL);
         if (ret_spec != NULL) {
@@ -12713,7 +12692,7 @@ Perl_flex_stat_int(pTHX_ const char *fspec, Stat_t *statbufp, int lstat_flag)
     }
 
     if (retval) {
-        /* Last chance - allow multiple dots with out EFS CHARSET */
+        /* Last chance - allow multiple dots without EFS CHARSET */
         /* The CRTL stat() falls down hard on multi-dot filenames in unix
          * format unless * DECC$EFS_CHARSET is in effect, so temporarily
          * enable it if it isn't already.
@@ -12752,8 +12731,8 @@ Perl_flex_stat_int(pTHX_ const char *fspec, Stat_t *statbufp, int lstat_flag)
 #endif
 
     if (!retval) {
-    char * cptr;
-    int rmsex_flags = PERL_RMSEXPAND_M_VMS;
+      char *cptr;
+      int rmsex_flags = PERL_RMSEXPAND_M_VMS;
 
       /* If this is an lstat, do not follow the link */
       if (lstat_flag)
@@ -12766,7 +12745,27 @@ Perl_flex_stat_int(pTHX_ const char *fspec, Stat_t *statbufp, int lstat_flag)
           decc$feature_set_value(decc_efs_charset_index, 1, 1);
       }
 #endif
-      cptr = int_rmsexpand_tovms(save_spec, statbufp->st_devnam, rmsex_flags);
+
+      /* If we've got a directory, save a fileified, expanded version of it
+       * in st_devnam.  If not a directory, just an expanded version.
+       */
+      if (S_ISDIR(statbufp->st_mode)) {
+          fileified = PerlMem_malloc(VMS_MAXRSS);
+          if (fileified == NULL)
+              _ckvmssts_noperl(SS$_INSFMEM);
+
+          cptr = do_fileify_dirspec(save_spec, fileified, 0, NULL);
+          if (cptr != NULL)
+              save_spec = fileified;
+      }
+
+      cptr = int_rmsexpand(save_spec, 
+                           statbufp->st_devnam,
+                           NULL,
+                           rmsex_flags,
+                           0,
+                           0);
+
 #if __CRTL_VER >= 70300000 && !defined(__VAX)
       if (efs_hack && (decc_efs_charset_index > 0)) {
           decc$feature_set_value(decc_efs_charset, 1, 0);
@@ -12803,8 +12802,10 @@ Perl_flex_stat_int(pTHX_ const char *fspec, Stat_t *statbufp, int lstat_flag)
     }
     /* If we were successful, leave errno where we found it */
     if (retval == 0) RESTORE_ERRNO;
-    PerlMem_free(temp_fspec);
-    PerlMem_free(fileified);
+    if (temp_fspec)
+        PerlMem_free(temp_fspec);
+    if (fileified)
+        PerlMem_free(fileified);
     return retval;
 
 }  /* end of flex_stat_int() */