Add testcase for TclGetBytesFromObj()

2 files changed, 18 insertions, 3 deletions

diff --git a/generic/tclTest.c b/generic/tclTest.c
index 9388110..d615d8b 100644
--- a/generic/tclTest.c
+++ b/generic/tclTest.c
@@ -5677,7 +5677,14 @@ TestbytestringObjCmd(
     int objc,			/* Number of arguments. */
     Tcl_Obj *const objv[])	/* The argument objects. */
 {
-    Tcl_Size n = 0;
+    struct {
+#if !defined(TCL_NO_DEPRECATED)
+	int n; /* On purpose, not Tcl_Size, in order to demonstrate what happens */
+#else
+	Tcl_Size n;
+#endif
+	int m; /* This variable should not be overwritten */
+    } x = {0, 1};
     const char *p;
 
     if (objc != 2) {
@@ -5685,11 +5692,15 @@ TestbytestringObjCmd(
 	return TCL_ERROR;
     }
 
-    p = (const char *)Tcl_GetBytesFromObj(interp, objv[1], &n);
+    p = (const char *)Tcl_GetBytesFromObj(interp, objv[1], &x.n);
     if (p == NULL) {
 	return TCL_ERROR;
     }
-    Tcl_SetObjResult(interp, Tcl_NewStringObj(p, n));
+    if (x.m != 1) {
+	Tcl_AppendResult(interp, "Tcl_GetBytesFromObj() overwrites variable", NULL);
+	return TCL_ERROR;
+    }
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(p, x.n));
     return TCL_OK;
 }
 
diff --git a/tests/binary.test b/tests/binary.test
index a947410..2984fec 100644
--- a/tests/binary.test
+++ b/tests/binary.test
@@ -20,6 +20,7 @@ catch [list package require -exact tcl::test [info patchlevel]]
 testConstraint bigEndian [expr {$tcl_platform(byteOrder) eq "bigEndian"}]
 testConstraint littleEndian [expr {$tcl_platform(byteOrder) eq "littleEndian"}]
 testConstraint testbytestring [llength [info commands testbytestring]]
+testConstraint pointerIs64bit [expr {$tcl_platform(pointerSize) >= 8}]
 
 # Big test for correct ordering of data in [expr]
 proc testIEEE {} {
@@ -3039,6 +3040,9 @@ test binary-80.3 {Tcl_GetBytesFromObj} -constraints testbytestring -returnCodes
 test binary-80.4 {Tcl_GetBytesFromObj} -constraints testbytestring -returnCodes 1 -body {
     testbytestring [testbytestring "\xC0\x80\xA0\xA0\xA0\xF0\x9F\x98\x81"]
 } -result "expected byte sequence but character 4 was '\U01F601' (U+01F601)"
+test binary-80.5 {Tcl_GetBytesFromObj} -constraints testbytestring -constraints pointerIs64bit -body {
+    testbytestring [string repeat A [expr 2**31]]
+} -returnCodes 1 -result "byte sequence length exceeds INT_MAX"
 
 # ----------------------------------------------------------------------
 # cleanup