8276661: Change getPathWithPrefixForWin32Calls to getPathWithPadForWi…

…n32Calls
openjdk · Nov 23, 2021 · 5703b01 · 5703b01
1 parent aecffaf
commit 5703b01
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Showing 2 changed files with 16 additions and 12 deletions.
diff --git a/src/java.base/windows/classes/sun/nio/fs/WindowsPath.java b/src/java.base/windows/classes/sun/nio/fs/WindowsPath.java
@@ -174,20 +174,23 @@ String getPathForPermissionCheck() {
     // use this path for Win32 calls
     // This method will prefix long paths with \\?\ or \\?\UNC as required.
     String getPathForWin32Calls() throws WindowsException {
-        return getPathForWin32Calls(false);
+        return getPathForWin32Calls(0);
     }
 
-    String getPathWithPrefixForWin32Calls() throws WindowsException {
-        return getPathForWin32Calls(true);
+    // This method will prefix long paths with \\?\ or \\?\UNC if
+    // path.length + pad > MAX_PATH. The parameter represents the
+    // length by which the path will be extended.
+    String getPathWithPadForWin32Calls(int pad) throws WindowsException {
+        return getPathForWin32Calls(Math.max(0, pad));
     }
 
-    private String getPathForWin32Calls(boolean forceLongPrefix) throws WindowsException {
-        // short absolute paths can be used directly
-        if (isAbsolute() && path.length() <= MAX_PATH)
-            return forceLongPrefix ? addPrefix(path) : path;
+    private String getPathForWin32Calls(int pad) throws WindowsException {
+        if (pad == 0) {
+            // short absolute paths can be used directly
+            if (isAbsolute() && path.length() <= MAX_PATH)
+                return path;
 
-        // return cached value if available
-        if (!forceLongPrefix) {
+            // return cached value if available
             WeakReference<String> ref = pathForWin32Calls;
             String cached = (ref != null) ? ref.get() : null;
             if (cached != null) {
@@ -204,7 +207,7 @@ private String getPathForWin32Calls(boolean forceLongPrefix) throws WindowsExcep
         // a link - for example, it is okay for foo/link/../bar to be changed
         // to foo/bar. The reason is that Win32 APIs to access foo/link/../bar
         // will access foo/bar anyway (which differs to Unix systems)
-        if (resolved.length() > MAX_PATH || forceLongPrefix) {
+        if (resolved.length() + pad > MAX_PATH) {
             if (resolved.length() > MAX_LONG_PATH) {
                 throw new WindowsException("Cannot access file with path exceeding "
                     + MAX_LONG_PATH + " characters");
@@ -215,7 +218,7 @@ private String getPathForWin32Calls(boolean forceLongPrefix) throws WindowsExcep
         // cache the resolved path (except drive relative paths as the working
         // directory on removal media devices can change during the lifetime
         // of the VM)
-        if (!forceLongPrefix && type != WindowsPathType.DRIVE_RELATIVE) {
+        if (pad == 0 && type != WindowsPathType.DRIVE_RELATIVE) {
             synchronized (this) {
                 pathForWin32Calls = new WeakReference<String>(resolved);
             }

diff --git a/src/java.base/windows/classes/sun/nio/fs/WindowsUserDefinedFileAttributeView.java b/src/java.base/windows/classes/sun/nio/fs/WindowsUserDefinedFileAttributeView.java
@@ -61,7 +61,8 @@ private String join(WindowsPath file, String name) throws WindowsException {
             throw new IllegalArgumentException("'name' has a root component");
         if (namePath.getParent() != null)
             throw new IllegalArgumentException("'name' has more than one element");
-        return join(file.getPathWithPrefixForWin32Calls(), name);
+        int pad = 1 + name.length();  // colon + name length
+        return join(file.getPathWithPadForWin32Calls(pad), name);
     }
 
     private final WindowsPath file;