From 4c530e8289ebf6ef84f7b17737da82ef4b9d38be Mon Sep 17 00:00:00 2001
From: s00478819 <sunjianye@huawei.com>
Date: Mon, 25 Oct 2021 17:11:19 +0800
Subject: [PATCH 1/3] 8273111: Default timezone should return zone ID if
 /etc/localtime is valid but not canonicalization on linux

---
 .../unix/native/libjava/TimeZone_md.c         |  61 +++----
 .../unix/native/libjava/canonicalize_md.c     | 146 +--------------
 src/java.base/unix/native/libjava/path_util.c | 166 ++++++++++++++++++
 src/java.base/unix/native/libjava/path_util.h |  31 ++++
 4 files changed, 230 insertions(+), 174 deletions(-)
 create mode 100644 src/java.base/unix/native/libjava/path_util.c
 create mode 100644 src/java.base/unix/native/libjava/path_util.h

diff --git a/src/java.base/unix/native/libjava/TimeZone_md.c b/src/java.base/unix/native/libjava/TimeZone_md.c
index 0780c3601..7eb22f186 100644
--- a/src/java.base/unix/native/libjava/TimeZone_md.c
+++ b/src/java.base/unix/native/libjava/TimeZone_md.c
@@ -41,6 +41,7 @@
 
 #include "jvm.h"
 #include "TimeZone_md.h"
+#include "path_util.h"
 
 static char *isFileIdentical(char* buf, size_t size, char *pathname);
 
@@ -83,6 +84,33 @@ static const char *ETC_ENVIRONMENT_FILE = "/etc/environment";
 
 #if defined(__linux__) || defined(MACOSX) || defined(__solaris__)
 
+/*
+ * remove repeated path separators ('/') in the given 'path'.
+ */
+static void
+removeDuplicateSlashes(char *path)
+{
+    char *left = path;
+    char *right = path;
+    char *end = path + strlen(path);
+
+    for (; right < end; right++) {
+        // Skip sequence of multiple path-separators.
+        while (*right == '/' && *(right + 1) == '/') {
+            right++;
+        }
+
+        while (*right != '\0' && !(*right == '/' && *(right + 1) == '/')) {
+            *left++ = *right++;
+        }
+
+        if (*right == '\0') {
+            *left = '\0';
+            break;
+        }
+    }
+}
+
 /*
  * Returns a pointer to the zone ID portion of the given zoneinfo file
  * name, or NULL if the given string doesn't contain "zoneinfo/".
@@ -312,36 +340,9 @@ getPlatformTimeZoneID()
             return NULL;
         }
         linkbuf[len] = '\0';
-
-        /* linkbuf may be a relative symlink or has more than one characters, like '.' and '/' ,
-         * which will cause the function call getZoneName return to an abnormal timeZone name.
-         * For example, linkbuf is "../usr/share/zoneinfo//Asia/Shanghai", then the call of
-         * getZoneName(linkbuf) will get "/Asia/Shanghai", not "Asia/Shanghai".
-         * So we covert it to an absolute path by adding the file's (which is define by macro
-         * DEFAULT_ZONEINFO_FILE) dirname and then call glibc's realpath API to canonicalize
-         * the path.
-         */
-        char abslinkbuf[2 * (PATH_MAX + 1)];
-        if (linkbuf[0] != '/') {
-            if (sprintf(abslinkbuf, "%s/%s", DEFAULT_ZONEINFO_FILE_DIRNAME, linkbuf) < 0) {
-                jio_fprintf(stderr, (const char *) "failed to generate absolute path\n");
-                return NULL;
-            }
-        } else {
-            strncpy(abslinkbuf, linkbuf, len + 1);
-        }
-
-        /* canonicalize the path */
-        char resolvedpath[PATH_MAX + 1];
-        resolvedpath[PATH_MAX] = '\0';
-        char *path = realpath(abslinkbuf, resolvedpath);
-        if (path == NULL) {
-            jio_fprintf(stderr, (const char *) "failed to get real path, symlink is %s\n",
-                        abslinkbuf);
-            return NULL;
-        }
-
-        tz = getZoneName(resolvedpath);
+        removeDuplicateSlashes(linkbuf);
+        collapse(linkbuf);
+        tz = getZoneName(linkbuf);
         if (tz != NULL) {
             tz = strdup(tz);
             return tz;
diff --git a/src/java.base/unix/native/libjava/canonicalize_md.c b/src/java.base/unix/native/libjava/canonicalize_md.c
index cb8ce69c8..d0e29b3eb 100644
--- a/src/java.base/unix/native/libjava/canonicalize_md.c
+++ b/src/java.base/unix/native/libjava/canonicalize_md.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1994, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -33,154 +33,12 @@
 #include <sys/stat.h>
 #include <errno.h>
 #include <limits.h>
-#if !defined(_ALLBSD_SOURCE)
-#include <alloca.h>
-#endif
+#include "path_util.h"
 
 
 /* Note: The comments in this file use the terminology
          defined in the java.io.File class */
 
-
-/* Check the given name sequence to see if it can be further collapsed.
-   Return zero if not, otherwise return the number of names in the sequence. */
-
-static int
-collapsible(char *names)
-{
-    char *p = names;
-    int dots = 0, n = 0;
-
-    while (*p) {
-        if ((p[0] == '.') && ((p[1] == '\0')
-                              || (p[1] == '/')
-                              || ((p[1] == '.') && ((p[2] == '\0')
-                                                    || (p[2] == '/'))))) {
-            dots = 1;
-        }
-        n++;
-        while (*p) {
-            if (*p == '/') {
-                p++;
-                break;
-            }
-            p++;
-        }
-    }
-    return (dots ? n : 0);
-}
-
-
-/* Split the names in the given name sequence,
-   replacing slashes with nulls and filling in the given index array */
-
-static void
-splitNames(char *names, char **ix)
-{
-    char *p = names;
-    int i = 0;
-
-    while (*p) {
-        ix[i++] = p++;
-        while (*p) {
-            if (*p == '/') {
-                *p++ = '\0';
-                break;
-            }
-            p++;
-        }
-    }
-}
-
-
-/* Join the names in the given name sequence, ignoring names whose index
-   entries have been cleared and replacing nulls with slashes as needed */
-
-static void
-joinNames(char *names, int nc, char **ix)
-{
-    int i;
-    char *p;
-
-    for (i = 0, p = names; i < nc; i++) {
-        if (!ix[i]) continue;
-        if (i > 0) {
-            p[-1] = '/';
-        }
-        if (p == ix[i]) {
-            p += strlen(p) + 1;
-        } else {
-            char *q = ix[i];
-            while ((*p++ = *q++));
-        }
-    }
-    *p = '\0';
-}
-
-
-/* Collapse "." and ".." names in the given path wherever possible.
-   A "." name may always be eliminated; a ".." name may be eliminated if it
-   follows a name that is neither "." nor "..".  This is a syntactic operation
-   that performs no filesystem queries, so it should only be used to cleanup
-   after invoking the realpath() procedure. */
-
-static void
-collapse(char *path)
-{
-    char *names = (path[0] == '/') ? path + 1 : path; /* Preserve first '/' */
-    int nc;
-    char **ix;
-    int i, j;
-    char *p, *q;
-
-    nc = collapsible(names);
-    if (nc < 2) return;         /* Nothing to do */
-    ix = (char **)alloca(nc * sizeof(char *));
-    splitNames(names, ix);
-
-    for (i = 0; i < nc; i++) {
-        int dots = 0;
-
-        /* Find next occurrence of "." or ".." */
-        do {
-            char *p = ix[i];
-            if (p[0] == '.') {
-                if (p[1] == '\0') {
-                    dots = 1;
-                    break;
-                }
-                if ((p[1] == '.') && (p[2] == '\0')) {
-                    dots = 2;
-                    break;
-                }
-            }
-            i++;
-        } while (i < nc);
-        if (i >= nc) break;
-
-        /* At this point i is the index of either a "." or a "..", so take the
-           appropriate action and then continue the outer loop */
-        if (dots == 1) {
-            /* Remove this instance of "." */
-            ix[i] = 0;
-        }
-        else {
-            /* If there is a preceding name, remove both that name and this
-               instance of ".."; otherwise, leave the ".." as is */
-            for (j = i - 1; j >= 0; j--) {
-                if (ix[j]) break;
-            }
-            if (j < 0) continue;
-            ix[j] = 0;
-            ix[i] = 0;
-        }
-        /* i will be incremented at the top of the loop */
-    }
-
-    joinNames(names, nc, ix);
-}
-
-
 /* Convert a pathname to canonical form.  The input path is assumed to contain
    no duplicate slashes.  On Solaris we can use realpath() to do most of the
    work, though once that's done we still must collapse any remaining "." and
diff --git a/src/java.base/unix/native/libjava/path_util.c b/src/java.base/unix/native/libjava/path_util.c
new file mode 100644
index 000000000..8a533f812
--- /dev/null
+++ b/src/java.base/unix/native/libjava/path_util.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#if !defined(_ALLBSD_SOURCE)
+#include <alloca.h>
+#endif
+#include "path_util.h"
+
+/* Check the given name sequence to see if it can be further collapsed.
+   Return zero if not, otherwise return the number of names in the sequence. */
+
+static int
+collapsible(char *names)
+{
+    char *p = names;
+    int dots = 0, n = 0;
+
+    while (*p) {
+        if ((p[0] == '.') && ((p[1] == '\0')
+                              || (p[1] == '/')
+                              || ((p[1] == '.') && ((p[2] == '\0')
+                                                    || (p[2] == '/'))))) {
+            dots = 1;
+        }
+        n++;
+        while (*p) {
+            if (*p == '/') {
+                p++;
+                break;
+            }
+            p++;
+        }
+    }
+    return (dots ? n : 0);
+}
+
+/* Split the names in the given name sequence,
+   replacing slashes with nulls and filling in the given index array */
+
+static void
+splitNames(char *names, char **ix)
+{
+    char *p = names;
+    int i = 0;
+
+    while (*p) {
+        ix[i++] = p++;
+        while (*p) {
+            if (*p == '/') {
+                *p++ = '\0';
+                break;
+            }
+            p++;
+        }
+    }
+}
+
+/* Join the names in the given name sequence, ignoring names whose index
+   entries have been cleared and replacing nulls with slashes as needed */
+
+static void
+joinNames(char *names, int nc, char **ix)
+{
+    int i;
+    char *p;
+
+    for (i = 0, p = names; i < nc; i++) {
+        if (!ix[i]) continue;
+        if (i > 0) {
+            p[-1] = '/';
+        }
+        if (p == ix[i]) {
+            p += strlen(p) + 1;
+        } else {
+            char *q = ix[i];
+            while ((*p++ = *q++));
+        }
+    }
+    *p = '\0';
+}
+
+/* Collapse "." and ".." names in the given path wherever possible.
+   A "." name may always be eliminated; a ".." name may be eliminated if it
+   follows a name that is neither "." nor "..".  This is a syntactic operation
+   that performs no filesystem queries, so it should only be used to cleanup
+   after invoking the realpath() procedure. */
+
+void
+collapse(char *path)
+{
+    char *names = (path[0] == '/') ? path + 1 : path; /* Preserve first '/' */
+    int nc;
+    char **ix;
+    int i, j;
+    char *p, *q;
+
+    nc = collapsible(names);
+    if (nc < 2) return;         /* Nothing to do */
+    ix = (char **)alloca(nc * sizeof(char *));
+    splitNames(names, ix);
+
+    for (i = 0; i < nc; i++) {
+        int dots = 0;
+
+        /* Find next occurrence of "." or ".." */
+        do {
+            char *p = ix[i];
+            if (p[0] == '.') {
+                if (p[1] == '\0') {
+                    dots = 1;
+                    break;
+                }
+                if ((p[1] == '.') && (p[2] == '\0')) {
+                    dots = 2;
+                    break;
+                }
+            }
+            i++;
+        } while (i < nc);
+        if (i >= nc) break;
+
+        /* At this point i is the index of either a "." or a "..", so take the
+           appropriate action and then continue the outer loop */
+        if (dots == 1) {
+            /* Remove this instance of "." */
+            ix[i] = 0;
+        }
+        else {
+            /* If there is a preceding name, remove both that name and this
+               instance of ".."; otherwise, leave the ".." as is */
+            for (j = i - 1; j >= 0; j--) {
+                if (ix[j]) break;
+            }
+            if (j < 0) continue;
+            ix[j] = 0;
+            ix[i] = 0;
+        }
+        /* i will be incremented at the top of the loop */
+    }
+
+    joinNames(names, nc, ix);
+}
diff --git a/src/java.base/unix/native/libjava/path_util.h b/src/java.base/unix/native/libjava/path_util.h
new file mode 100644
index 000000000..7b0fd5eb1
--- /dev/null
+++ b/src/java.base/unix/native/libjava/path_util.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef PATH_UTIL_H
+#define PATH_UTIL_H
+
+void collapse(char *path);
+
+#endif
-- 
2.22.0