[PATCH v4 1/3] xcopy: Don't attempt to copy a file to itself.

[Joe Souza]

From: Joe Souza

---
 programs/xcopy/xcopy.c  | 62 ++++++++++++++++++++++++++++++++++-------
 programs/xcopy/xcopy.h  |  1 +
 programs/xcopy/xcopy.rc |  1 +
 3 files changed, 54 insertions(+), 10 deletions(-)

diff --git a/programs/xcopy/xcopy.c b/programs/xcopy/xcopy.c
index ee30e07b184..3bb00d917e5 100644
--- a/programs/xcopy/xcopy.c
+++ b/programs/xcopy/xcopy.c
@@ -325,6 +325,37 @@ static BOOL XCOPY_ProcessExcludeList(WCHAR* parms) {
     return FALSE;
 }

+/* =========================================================================
+ * XCOPY_IsSameFile
+ *
+ * Checks if the two paths reference to the same file.
+ * Copied from WCMD builtins.c, and tab-adjusted.
+ * ========================================================================= */
+static BOOL XCOPY_IsSameFile(const WCHAR *name1, const WCHAR *name2)
+{
+    BOOL ret = FALSE;
+    HANDLE file1 = INVALID_HANDLE_VALUE, file2 = INVALID_HANDLE_VALUE;
+    BY_HANDLE_FILE_INFORMATION info1, info2;
+
+    file1 = CreateFileW(name1, 0, FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING, 0, 0);
+    if (file1 == INVALID_HANDLE_VALUE || !GetFileInformationByHandle(file1, &info1))
+        goto end;
+
+    file2 = CreateFileW(name2, 0, FILE_SHARE_DELETE | FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_EXISTING, 0, 0);
+    if (file2 == INVALID_HANDLE_VALUE || !GetFileInformationByHandle(file2, &info2))
+        goto end;
+
+    ret = info1.dwVolumeSerialNumber == info2.dwVolumeSerialNumber
+        && info1.nFileIndexHigh == info2.nFileIndexHigh
+        && info1.nFileIndexLow == info2.nFileIndexLow;
+end:
+    if (file1 != INVALID_HANDLE_VALUE)
+        CloseHandle(file1);
+    if (file2 != INVALID_HANDLE_VALUE)
+        CloseHandle(file2);
+    return ret;
+}
+
 /* =========================================================================
    XCOPY_DoCopy - Recursive function to copy files based on input parms
      of a stem and a spec
@@ -345,7 +376,7 @@ static int XCOPY_DoCopy(WCHAR *srcstem, WCHAR *srcspec,
     WCHAR           *inputpath, *outputpath;
     BOOL            copiedFile = FALSE;
     DWORD           destAttribs, srcAttribs;
-    BOOL            skipFile;
+    BOOL            skipFile, quitCopy = FALSE;
     int             ret = 0;

/* Allocate some working memory on heap to minimize footprint */
@@ -359,7 +390,7 @@ static int XCOPY_DoCopy(WCHAR *srcstem, WCHAR *srcspec,

/* Search 1 - Look for matching files */
     h = FindFirstFileW(inputpath, finddata);
-    while (h != INVALID_HANDLE_VALUE && findres) {
+    while (h != INVALID_HANDLE_VALUE && !quitCopy && findres) {

skipFile = FALSE;

@@ -465,6 +496,18 @@ static int XCOPY_DoCopy(WCHAR *srcstem, WCHAR *srcspec,
                 }
             }

+            /* Don't copy a file over itself. */
+            if (XCOPY_IsSameFile(copyFrom, copyTo)) {
+                skipFile = quitCopy = TRUE;
+                if (!(flags & OPT_QUIET)) {
+                    if (flags & OPT_FULL)
+                        XCOPY_wprintf(L"%1 -> %2\n", copyFrom, copyTo);
+                    else
+                        XCOPY_wprintf(L"%1\n", copyFrom);
+                }
+                XCOPY_wprintf(XCOPY_LoadMessage(STRING_NOCOPYTOSELF));
+            }
+
             /* Prompt each file if necessary */
             if (!skipFile && (flags & OPT_SRCPROMPT)) {
                 DWORD count;
@@ -550,11 +593,10 @@ static int XCOPY_DoCopy(WCHAR *srcstem, WCHAR *srcspec,
                            copyFrom, copyTo, error);
                     XCOPY_FailMessage(error);

-                    if (flags & OPT_IGNOREERRORS) {
-                        skipFile = TRUE;
-                    } else {
+                    skipFile = TRUE;
+                    if (!(flags & OPT_IGNOREERRORS)) {
                         ret = RC_WRITEERROR;
-                        goto cleanup;
+                        quitCopy = TRUE;
                     }
                 } else {

@@ -580,12 +622,14 @@ static int XCOPY_DoCopy(WCHAR *srcstem, WCHAR *srcspec,
         }

/* Find next file */
-        findres = FindNextFileW(h, finddata);
+        if (!quitCopy) {
+            findres = FindNextFileW(h, finddata);
+        }
     }
     FindClose(h);

/* Search 2 - do subdirs */
-    if (flags & OPT_RECURSIVE) {
+    if (!quitCopy && (flags & OPT_RECURSIVE)) {

/* If /E is supplied, create the directory now */
         if ((flags & OPT_EMPTYDIR) &&
@@ -628,8 +672,6 @@ static int XCOPY_DoCopy(WCHAR *srcstem, WCHAR *srcspec,
         FindClose(h);
     }

-cleanup:
-
     /* free up memory */
     HeapFree(GetProcessHeap(), 0, finddata);
     HeapFree(GetProcessHeap(), 0, inputpath);
diff --git a/programs/xcopy/xcopy.h b/programs/xcopy/xcopy.h
index 1ed9e20c45b..70b0935ba2c 100644
--- a/programs/xcopy/xcopy.h
+++ b/programs/xcopy/xcopy.h
@@ -69,3 +69,4 @@
 #define STRING_FILE_CHAR        115
 #define STRING_DIR_CHAR         116
 #define STRING_HELP             117
+#define STRING_NOCOPYTOSELF     118
diff --git a/programs/xcopy/xcopy.rc b/programs/xcopy/xcopy.rc
index c61e4da88fd..b12eeb4b068 100644
--- a/programs/xcopy/xcopy.rc
+++ b/programs/xcopy/xcopy.rc
@@ -79,4 +79,5 @@ Where:\n\
 \t\tIf no date is supplied, only copy if destination is older\n\
 \t\tthan source.\n\n"

+    STRING_NOCOPYTOSELF, "File cannot be copied to itself.\n"
 }