1 files changed, 43 insertions, 9 deletions

diff --git a/generic/tclStubLib.c b/generic/tclStubLib.c
index 0efaf50..96f7f2f 100644
--- a/generic/tclStubLib.c
+++ b/generic/tclStubLib.c
@@ -34,11 +34,12 @@ const TclIntPlatStubs *tclIntPlatStubsPtr = NULL;
 
 static const TclStubs *
 HasStubSupport(
-    Tcl_Interp *interp)
+    Tcl_Interp *interp,
+    int magic)
 {
     Interp *iPtr = (Interp *) interp;
-
-    if (iPtr->stubTable && (iPtr->stubTable->magic == TCL_STUB_MAGIC)) {
+    if (iPtr->stubTable && iPtr->stubTable->magic == magic
+	    && iPtr->stubTable->magic == TCL_STUB_MAGIC) {
 	return iPtr->stubTable;
     }
     iPtr->result = (char *) "interpreter uses an incompatible stubs mechanism";
@@ -58,7 +59,7 @@ static int isDigit(const int c)
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_InitStubs --
+ * TclInitStubs --
  *
  *	Tries to initialise the stub table pointers and ensures that the
  *	correct version of Tcl is loaded.
@@ -74,13 +75,19 @@ static int isDigit(const int c)
  */
 
 MODULE_SCOPE const char *
-Tcl_InitStubs(
+TclInitStubs(
     Tcl_Interp *interp,
     const char *version,
-    int exact)
+    int exact,
+    const char *tclversion,
+    int magic)
 {
+    const char *p;
+    char *q;
+    char major[TCL_INTEGER_SPACE];
     const char *actualVersion = NULL;
     ClientData pkgData = NULL;
+    Interp *iPtr = (Interp *) interp;
 
     /*
      * We can't optimize this check by caching tclStubsPtr because that
@@ -88,24 +95,51 @@ Tcl_InitStubs(
      * times. [Bug 615304]
      */
 
-    tclStubsPtr = HasStubSupport(interp);
+    tclStubsPtr = HasStubSupport(interp, magic);
     if (!tclStubsPtr) {
 	return NULL;
     }
 
+    /*
+     * Check that the [load]ing interp and [load]ed extension were compiled
+     * against headers from the same major version of Tcl.  If not, they
+     * will not agree on the layout of the stubs and will crash.  Report
+     * the error instead of crashing.
+     */
+
+    p = tclversion;
+    q = major;
+    while (isDigit(*p)) {
+	*q++ = *p++;
+	if (q-major > TCL_INTEGER_SPACE) {
+	    iPtr->result = (char *) "major version overflow";
+	    iPtr->freeProc = TCL_STATIC;
+	    return NULL;
+	}
+    }
+    *q = '\0';
+
+    if (NULL == Tcl_PkgRequireEx(interp, "Tcl", major, 0, NULL)) {
+	return NULL;
+    }
+
+    /*
+     * Check satisfaction of the requirement requested by the caller.
+     */
+
     actualVersion = Tcl_PkgRequireEx(interp, "Tcl", version, 0, &pkgData);
     if (actualVersion == NULL) {
 	return NULL;
     }
     if (exact) {
-	const char *p = version;
 	int count = 0;
 
+	p = version;
 	while (*p) {
 	    count += !isDigit(*p++);
 	}
 	if (count == 1) {
-	    const char *q = actualVersion;
+	    q = actualVersion;
 
 	    p = version;
 	    while (*p && (*p == *q)) {