Paths starting with "//?/" on Windows are local

The prefix might be used to support paths longer than MAX_PATH. https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#win32-file-namespaces Signed-off-by: Torbjörn SVENSSON <[email protected]>
eclipse-equinox · Jan 15, 2024 · cfb0c9e · cfb0c9e
1 parent e2267e3
commit cfb0c9e
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diff --git a/bundles/org.eclipse.equinox.common.tests/src/org/eclipse/equinox/common/tests/PathTest.java b/bundles/org.eclipse.equinox.common.tests/src/org/eclipse/equinox/common/tests/PathTest.java
@@ -318,6 +318,23 @@ public void testConstructors() {
 		assertEquals("3.0.win", "D:/foo/abc.txt", IPath.forWindows("/D:/foo/abc.txt").toString());
 		// fullPath = new java.io.File("D:/").toURL().getPath()
 		assertEquals("3.1.win", "D:/", IPath.forWindows("/D:/").toString());
+
+		final String verylongpath = "C:/dev/verylongpath/00112233445566778899aabbccddeeff/00112233445566778899aabbccddeeff/00112233445566778899aabbccddeeff/"
+				+ "00112233445566778899aabbccddeeff/00112233445566778899aabbccddeeff/00112233445566778899aabbccddeeff/root/lib/gcc/arm-none-eabi/7.3.1/include-fixed";
+		anyPath = IPath.forWindows(verylongpath);
+		assertEquals("3.2.1.win", "C:", anyPath.getDevice());
+		assertEquals("3.2.2.win", "dev", anyPath.segment(0));
+		assertEquals("3.2.3.win", verylongpath, anyPath.toString());
+
+		anyPath = IPath.forWindows("//?/" + verylongpath);
+		assertEquals("3.3.1.win", "C:", anyPath.getDevice());
+		assertEquals("3.3.2.win", "dev", anyPath.segment(0));
+		assertEquals("3.3.3.win", verylongpath, anyPath.toString());
+
+		anyPath = IPath.forWindows("\\\\?\\" + verylongpath.replace('/', '\\'));
+		assertEquals("3.4.1.win", "C:", anyPath.getDevice());
+		assertEquals("3.4.2.win", "dev", anyPath.segment(0));
+		assertEquals("3.4.3.win", verylongpath, anyPath.toString());
 	}
 
 	@Test

diff --git a/bundles/org.eclipse.equinox.common/src/org/eclipse/core/runtime/Path.java b/bundles/org.eclipse.equinox.common/src/org/eclipse/core/runtime/Path.java
@@ -310,8 +310,15 @@ private static String backslashToForward(String path, boolean forWindows) {
 			// extract device
 			int i = fullPath.indexOf(DEVICE_SEPARATOR);
 			if (i != -1) {
-				// remove leading slash from device part to handle output of URL.getFile()
-				int start = fullPath.charAt(0) == SEPARATOR ? 1 : 0;
+				int start = 0;
+				if (fullPath.startsWith("//?/")) { //$NON-NLS-1$
+					// Paths prefixed with "//?/" are local paths. For details:
+					// https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#win32-file-namespaces
+					start = 4;
+				} else if (fullPath.charAt(0) == SEPARATOR) {
+					// remove leading slash from device part to handle output of URL.getFile()
+					start = 1;
+				}
 				devicePart = fullPath.substring(start, i + 1);
 				fullPath = fullPath.substring(i + 1, fullPath.length());
 			}