1 files changed, 65 insertions, 31 deletions

diff --git a/generic/tclStubLib.c b/generic/tclStubLib.c
index cadb7b9..6c89562 100644
--- a/generic/tclStubLib.c
+++ b/generic/tclStubLib.c
@@ -60,57 +60,91 @@ Tcl_InitStubs(
     ClientData pkgData = NULL;
     const TclStubs *stubsPtr = iPtr->stubTable;
 
+    /* Compatibility with Tcl8. If "exact" has the value 0 or 1, then parameters
+     * tclversion and magic are not used, so fill in the right Tcl8 values. */
+    if ((exact|1) == 1) {
+	tclversion = "8";
+	magic = TCL_STUB_MAGIC;
+	exact |= (int)sizeof(int);
+    }
     /*
      * We can't optimize this check by caching tclStubsPtr because that
      * prevents apps from being able to load/unload Tcl dynamically multiple
      * times. [Bug 615304]
      */
 
-    if (!stubsPtr || (stubsPtr->magic != TCL_STUB_MAGIC)) {
-	iPtr->legacyResult = "interpreter uses an incompatible stubs mechanism";
-	iPtr->legacyFreeProc = 0; /* TCL_STATIC */
-	return NULL;
-    }
-
-    actualVersion = stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 0, &pkgData);
-    if (actualVersion == NULL) {
+    if (!stubsPtr || (stubsPtr->magic != magic)) {
+	/* This can only be executed in a Tcl < 8.1 interpreter, because
+	 * the magic values are kept the same in later versions. */
+	iPtr->objResultPtr = (Tcl_Obj *)
+		"interpreter uses an incompatible stubs mechanism";
+	iPtr->emptyObjPtr = 0; /* TCL_STATIC */
 	return NULL;
     }
-    if (exact&1) {
-	const char *p = version;
-	int count = 0;
 
-	while (*p) {
-	    count += !ISDIGIT(*p++);
+    if(iPtr->errorLine == TCL_STUB_MAGIC) {
+	actualVersion = (const char *)iPtr->objResultPtr;
+	tclStubsPtr = stubsPtr;
+    } else {
+	actualVersion = stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 0, &pkgData);
+	if (actualVersion == NULL) {
+	    return NULL;
 	}
-	if (count == 1) {
-	    const char *q = actualVersion;
+	if (exact&1) {
+	    const char *p = version;
+	    int count = 0;
+
+	    while (*p) {
+		count += !ISDIGIT(*p++);
+	    }
+	    if (count == 1) {
+		const char *q = actualVersion;
 
-	    p = version;
-	    while (*p && (*p == *q)) {
-		p++; q++;
+		p = version;
+		while (*p && (*p == *q)) {
+		    p++; q++;
+		}
+		if (*p || ISDIGIT(*q)) {
+		    /* Construct error message */
+		    stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 1, NULL);
+		    return NULL;
+		}
+		} else {
+		actualVersion = stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 1, NULL);
+		if (actualVersion == NULL) {
+		    return NULL;
+		}
 	    }
-	    if (*p || ISDIGIT(*q)) {
-		/* Construct error message */
-		stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 1, NULL);
+	}
+
+#define MASK (4+8+16) /* possible values of sizeof(size_t) */
+
+	if (stubsPtr->reserved77) {
+	    /* We are running Tcl 8. */
+	    if ((exact & MASK) != (int)sizeof(int)) {
+		char msg[32], *p = msg;
+
+		/* Take "version", but strip off everything after '-' */
+		while (*version && *version != '-') {
+		    *p++ = *version++;
+		}
+		*p = '\0';
+		stubsPtr->tcl_AppendResult(interp, "incompatible stub library: have ",
+			tclversion, ", need ", msg, NULL);
 		return NULL;
 	    }
+	    tclStubsPtr = (TclStubs *)pkgData;
 	} else {
-	    actualVersion = stubsPtr->tcl_PkgRequireEx(interp, "Tcl", version, 1, NULL);
-	    if (actualVersion == NULL) {
+	    /* We are running Tcl 9. */
+	    if ((exact & MASK) != (int)sizeof(size_t)) {
+		stubsPtr->tcl_AppendResult(interp, "incompatible stub library: have ",
+			tclversion, ", need 9", NULL);
 		return NULL;
 	    }
+	    tclStubsPtr = stubsPtr;
 	}
     }
 
-    if (stubsPtr->reserved77) {
-	/* We are running Tcl 8. Do some additional checks here. */
-	tclStubsPtr = (TclStubs *)pkgData;
-    } else {
-	/* We are running Tcl 9. Do some additional checks here. */
-	tclStubsPtr = stubsPtr;
-    }
-
     if (tclStubsPtr->hooks) {
 	tclPlatStubsPtr = tclStubsPtr->hooks->tclPlatStubs;
 	tclIntStubsPtr = tclStubsPtr->hooks->tclIntStubs;