Merge bug-3588687

2 files changed, 53 insertions, 7 deletions

diff --git a/generic/tcl.h b/generic/tcl.h
index fa6afe4..c7b9e6a 100644
--- a/generic/tcl.h
+++ b/generic/tcl.h
@@ -2281,8 +2281,8 @@ typedef int (Tcl_NRPostProc) (ClientData data[], Tcl_Interp *interp,
  * main library in case an extension is statically linked into an application.
  */
 
-const char *		Tcl_InitStubs(Tcl_Interp *interp, const char *version,
-			    int exact);
+const char *		TclInitStubs(Tcl_Interp *interp, const char *version,
+			    int exact, int major, int magic);
 const char *		TclTomMathInitializeStubs(Tcl_Interp *interp,
 			    const char *version, int epoch, int revision);
 
@@ -2290,7 +2290,10 @@ const char *		TclTomMathInitializeStubs(Tcl_Interp *interp,
  * When not using stubs, make it a macro.
  */
 
-#ifndef USE_TCL_STUBS
+#ifdef USE_TCL_STUBS
+#define Tcl_InitStubs(interp, version, exact) \
+    TclInitStubs(interp, version, exact, TCL_MAJOR_VERSION, TCL_STUB_MAGIC)
+#else
 #define Tcl_InitStubs(interp, version, exact) \
     Tcl_PkgInitStubsCheck(interp, version, exact)
 #endif
diff --git a/generic/tclStubLib.c b/generic/tclStubLib.c
index fe1302c..e875bf7 100644
--- a/generic/tclStubLib.c
+++ b/generic/tclStubLib.c
@@ -101,13 +101,56 @@ static int isDigit(const int c)
  */
 
 MODULE_SCOPE const char *
-Tcl_InitStubs(
+TclInitStubs(
     Tcl_Interp *interp,
     const char *version,
-    int exact)
+    int exact,
+    int major,
+    int magic)
 {
+    Interp *iPtr = (Interp *) interp;
     const char *actualVersion = NULL;
     ClientData pkgData = NULL;
+    const char *p, *q;
+
+    /*
+     * Detect whether the extension and the stubs library were built
+     * against Tcl header files declaring use of incompatible stubs
+     * mechanisms.  Even within the same mechanism, also detect if
+     * the header files are from different major versions.  Either
+     * is seriously broken.  An extension and its stubs library ought
+     * to share compatible headers, if not the same one.
+     */
+
+    if (magic != TCL_STUB_MAGIC || major != TCL_MAJOR_VERSION) {
+	iPtr->legacyResult =
+	    (char *) "extension linked to incompatible stubs library";
+	iPtr->legacyFreeProc = TCL_STATIC;
+	return NULL;
+    }
+
+    /*
+     * Detect whether an extension compiled against a Tcl header file
+     * of one major version is requesting to use a stubs table of a
+     * different major version.  According to our compat rules, that's
+     * a request that cannot succeed.  Different major versions imply
+     * incompatible stub tables.
+     */
+
+    p = version;
+    q = TCL_VERSION;
+    while (isDigit(*p)) {
+	if (*p++ != *q++) {
+	    goto badVersion;
+	}
+    }
+    if (isDigit(*q)) {
+    badVersion:
+	iPtr->legacyResult =
+	    (char *) "extension passed bad version argument to stubs library";
+	iPtr->legacyFreeProc = TCL_STATIC;
+	return NULL;
+    }
 
     /*
      * We can't optimize this check by caching tclStubsPtr because that
@@ -125,14 +168,14 @@ Tcl_InitStubs(
 	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)) {