Dict refcount fixes from Peter Spjuth. Thanks! [Bug 876170]

3 files changed, 219 insertions, 20 deletions

diff --git a/ChangeLog b/ChangeLog
index eafe1c2..7c7f167 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2004-01-14  Donal K. Fellows  <donal.k.fellows@man.ac.uk>
+
+	* generic/tclDictObj.c: Assorted dict fixes from Peter Spjuth
+	relating to [Bug 876170].
+	(SetDictFromAny): Make sure that lists retain their ordering even
+	when converted to dictionaries and back.
+	(TraceDictPath): Correct object reference count handling!
+	(DictReplaceCmd, DictRemoveCmd): Stop object leak.
+	(DictIncrCmd,DictLappendCmd,DictAppendCmd,DictSetCmd,DictUnsetCmd): 
+	Simpler handling of reference counts when assigning to variables.
+	* tests/dict.test (dict-19.2): Memory leak stress test
+
 2004-01-13  Don Porter	<dgp@users.sourceforge.net>
 
 	* generic/tclCmdMZ.c (Tcl_SwitchObjCmd):  Silence compiler warnings.
diff --git a/generic/tclDictObj.c b/generic/tclDictObj.c
index 5fbedd8..5d9fb9a 100644
--- a/generic/tclDictObj.c
+++ b/generic/tclDictObj.c
@@ -9,7 +9,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclDictObj.c,v 1.12 2003/12/24 04:18:19 davygrvy Exp $
+ * RCS: @(#) $Id: tclDictObj.c,v 1.13 2004/01/14 09:34:33 dkf Exp $
  */
 
 #include "tclInt.h"
@@ -373,6 +373,15 @@ SetDictFromAny(interp, objPtr)
 	}
 
 	/*
+	 * If the list is shared its string rep must not be lost so it
+	 * still is the same list.
+	 */
+
+	if (Tcl_IsShared(objPtr)) {
+	    (void) Tcl_GetString(objPtr);
+	}
+
+	/*
 	 * Build the hash of key/value pairs.
 	 */
 	dict = (Dict *) ckalloc(sizeof(Dict));
@@ -594,6 +603,7 @@ TraceDictPath(interp, dictPtr, keyc, keyv, willUpdate)
 	    if (Tcl_IsShared(tmpObj)) {
 		Tcl_DecrRefCount(tmpObj);
 		tmpObj = Tcl_DuplicateObj(tmpObj);
+		Tcl_IncrRefCount(tmpObj);
 		Tcl_SetHashValue(hPtr, (ClientData) tmpObj);
 		dict->epoch++;
 		newDict = (Dict *) tmpObj->internalRep.otherValuePtr;
@@ -1355,6 +1365,7 @@ DictReplaceCmd(interp, objc, objv)
 {
     Tcl_Obj *dictPtr;
     int i, result;
+    int allocatedDict = 0;
 
     if ((objc < 3) || !(objc & 1)) {
 	Tcl_WrongNumArgs(interp, 2, objv, "dictionary ?key value ...?");
@@ -1364,10 +1375,14 @@ DictReplaceCmd(interp, objc, objv)
     dictPtr = objv[2];
     if (Tcl_IsShared(dictPtr)) {
 	dictPtr = Tcl_DuplicateObj(dictPtr);
+	allocatedDict = 1;
     }
     for (i=3 ; i<objc ; i+=2) {
 	result = Tcl_DictObjPut(interp, dictPtr, objv[i], objv[i+1]);
 	if (result != TCL_OK) {
+	    if (allocatedDict) {
+		Tcl_DecrRefCount(dictPtr);
+	    }
 	    return TCL_ERROR;
 	}
     }
@@ -1401,6 +1416,7 @@ DictRemoveCmd(interp, objc, objv)
 {
     Tcl_Obj *dictPtr;
     int i, result;
+    int allocatedDict = 0;
 
     if (objc < 3) {
 	Tcl_WrongNumArgs(interp, 2, objv, "dictionary ?key ...?");
@@ -1410,10 +1426,14 @@ DictRemoveCmd(interp, objc, objv)
     dictPtr = objv[2];
     if (Tcl_IsShared(dictPtr)) {
 	dictPtr = Tcl_DuplicateObj(dictPtr);
+	allocatedDict = 1;
     }
     for (i=3 ; i<objc ; i++) {
 	result = Tcl_DictObjRemove(interp, dictPtr, objv[i]);
 	if (result != TCL_OK) {
+	    if (allocatedDict) {
+		Tcl_DecrRefCount(dictPtr);
+	    }
 	    return TCL_ERROR;
 	}
     }
@@ -1685,6 +1705,7 @@ DictIncrCmd(interp, objc, objv)
     int result, isWide = 0;
     long incrValue = 1;
     Tcl_WideInt wideIncrValue = 0;
+    int allocatedDict = 0;
 
     if (objc < 4 || objc > 5) {
 	Tcl_WrongNumArgs(interp, 2, objv, "varName key ?increment?");
@@ -1714,6 +1735,7 @@ DictIncrCmd(interp, objc, objv)
 
     dictPtr = Tcl_ObjGetVar2(interp, objv[2], NULL, 0);
     if (dictPtr == NULL) {
+	allocatedDict = 1;
 	dictPtr = Tcl_NewDictObj();
 	if (isWide) {
 	    valuePtr = Tcl_NewWideIntObj(wideIncrValue);
@@ -1726,10 +1748,14 @@ DictIncrCmd(interp, objc, objv)
 	Tcl_WideInt wValue;
 
 	if (Tcl_IsShared(dictPtr)) {
+	    allocatedDict = 1;
 	    dictPtr = Tcl_DuplicateObj(dictPtr);
 	}
 
 	if (Tcl_DictObjGet(interp, dictPtr, objv[3], &valuePtr) != TCL_OK) {
+	    if (allocatedDict) {
+		Tcl_DecrRefCount(dictPtr);
+	    }
 	    return TCL_ERROR;
 	}
 	if (valuePtr == NULL) {
@@ -1785,6 +1811,9 @@ DictIncrCmd(interp, objc, objv)
 	     */
 	    result = Tcl_GetWideIntFromObj(interp, valuePtr, &wValue);
 	    if (result != TCL_OK) {
+		if (allocatedDict) {
+		    Tcl_DecrRefCount(dictPtr);
+		}
 		return result;
 	    }
 	    /*
@@ -1818,15 +1847,23 @@ DictIncrCmd(interp, objc, objv)
 	    }
 	}
 	if (Tcl_DictObjPut(interp, dictPtr, objv[3], valuePtr) != TCL_OK) {
+	    /* 
+	     * This shouldn't happen since dictPtr is known
+	     * from above to be a valid dictionary.
+	     */
+	    if (allocatedDict) {
+		Tcl_DecrRefCount(dictPtr);
+	    }
 	    Tcl_DecrRefCount(valuePtr);
 	    return TCL_ERROR;
 	}
     }
   valueAlreadyInDictionary:
+    Tcl_IncrRefCount(dictPtr);
     resultPtr = Tcl_ObjSetVar2(interp, objv[2], NULL, dictPtr,
 	    TCL_LEAVE_ERR_MSG);
+    Tcl_DecrRefCount(dictPtr);
     if (resultPtr == NULL) {
-	Tcl_DecrRefCount(dictPtr);
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, resultPtr);
@@ -1910,12 +1947,11 @@ DictLappendCmd(interp, objc, objv)
 	Tcl_InvalidateStringRep(dictPtr);
     }
 
+    Tcl_IncrRefCount(dictPtr);
     resultPtr = Tcl_ObjSetVar2(interp, objv[2], NULL, dictPtr,
 	    TCL_LEAVE_ERR_MSG);
+    Tcl_DecrRefCount(dictPtr);
     if (resultPtr == NULL) {
-	if (allocatedDict) {
-	    Tcl_DecrRefCount(dictPtr);
-	}
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, resultPtr);
@@ -1984,12 +2020,11 @@ DictAppendCmd(interp, objc, objv)
 
     Tcl_DictObjPut(interp, dictPtr, objv[3], valuePtr);
 
+    Tcl_IncrRefCount(dictPtr);
     resultPtr = Tcl_ObjSetVar2(interp, objv[2], NULL, dictPtr,
 	    TCL_LEAVE_ERR_MSG);
+    Tcl_DecrRefCount(dictPtr);
     if (resultPtr == NULL) {
-	if (allocatedDict) {
-	    Tcl_DecrRefCount(dictPtr);
-	}
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, resultPtr);
@@ -2188,12 +2223,11 @@ DictSetCmd(interp, objc, objv)
 	return TCL_ERROR;
     }
 
+    Tcl_IncrRefCount(dictPtr);
     resultPtr = Tcl_ObjSetVar2(interp, objv[2], NULL, dictPtr,
 	    TCL_LEAVE_ERR_MSG);
+    Tcl_DecrRefCount(dictPtr);
     if (resultPtr == NULL) {
-	if (allocatedDict) {
-	    Tcl_DecrRefCount(dictPtr);
-	}
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, resultPtr);
@@ -2249,12 +2283,11 @@ DictUnsetCmd(interp, objc, objv)
 	return TCL_ERROR;
     }
 
+    Tcl_IncrRefCount(dictPtr);
     resultPtr = Tcl_ObjSetVar2(interp, objv[2], NULL, dictPtr,
 	    TCL_LEAVE_ERR_MSG);
+    Tcl_DecrRefCount(dictPtr);
     if (resultPtr == NULL) {
-	if (allocatedDict) {
-	    Tcl_DecrRefCount(dictPtr);
-	}
 	return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, resultPtr);
diff --git a/tests/dict.test b/tests/dict.test
index e4d5994..c7ea06d 100644
--- a/tests/dict.test
+++ b/tests/dict.test
@@ -9,13 +9,16 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: dict.test,v 1.4 2003/10/06 14:32:22 dgp Exp $
+# RCS: @(#) $Id: dict.test,v 1.5 2004/01/14 09:34:33 dkf Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest 2
     namespace import -force ::tcltest::*
 }
 
+# Used for constraining memory leak tests
+testConstraint memory [llength [info commands memory]]
+
 # Procedure to help check the contents of a dictionary.  Note that we
 # can't just compare the string version because the order of the
 # elements is (deliberately) not defined.  This is because it is
@@ -64,11 +67,11 @@ test dict-2.5 {dict create command} {
 } {1 {wrong # args: should be "dict create ?key value ...?"}}
 test dict-2.6 {dict create command - initialse refcount field!} {
     # Bug 715751 will show up in memory debuggers like purify
-    for {set i 0} {$i<10} {incr i} { 
-	set dictv [dict create a 0] 
-	set share [dict values $dictv] 
-	list [dict incr dictv a] 
-    } 
+    for {set i 0} {$i<10} {incr i} {
+	set dictv [dict create a 0]
+	set share [dict values $dictv]
+	list [dict incr dictv a]
+    }
 } {}
 test dict-2.7 {dict create command - #-quoting in string rep} {
     dict create # #comment
@@ -136,6 +139,7 @@ test dict-4.8 {dict replace command} {
     list [catch {dict replace [list a a a] a b} msg] $msg
 } {1 {missing value to go with key}}
 test dict-4.9 {dict replace command} {dict replace [list a a] a b} {a b}
+test dict-4.10 {dict replace command} {dict replace [list a a] a b a c} {a c}
 
 test dict-5.1 {dict remove command} {dict remove {a b c d} a} {c d}
 test dict-5.2 {dict remove command} {dict remove {a b c d} c} {a b}
@@ -711,6 +715,156 @@ test dict-17.23 {dict filter command} {
     list [catch {dict filter a key *} msg] $msg
 } {1 {missing value to go with key}}
 
+test dict-18.1 {dict-list relationship} {
+    -body {
+        # Test that any internal conversion between list and dict
+        # does not change the object
+        set l [list 1 2 3 4 5 6 7 8 9 0 q w e r t y]
+        dict values $l
+        set l
+    }
+    -result {1 2 3 4 5 6 7 8 9 0 q w e r t y}
+}
+test dict-18.2 {dict-list relationship} {
+    -body {
+        # Test that the dictionary is a valid list
+        set d [dict create "abc def" 0 "a\{b" 1 "c\}d" 2]
+        for {set t 0} {$t < 5} {incr t} {
+            llength $d
+            dict lappend d "abc def" "\}\{"
+            dict append  d "a\{b" "\}"
+            dict incr    d "c\}d" 1
+        }
+        llength $d
+    }
+    -result 6
+}
+
+# This is a test for a specific bug.
+# It shows a bad ref counter when running with memdebug on.
+test dict-19.1 {memory bug} -setup {
+    proc xxx {} {
+        set successors [dict create x {c d}]
+        dict set successors x a b
+        dict get $successors x
+    }
+} -body {
+    xxx
+} -cleanup {
+    rename xxx {}
+} -result [dict create c d a b]
+test dict-19.2 {dict: testing for leaks} -setup {
+    proc getbytes {} {
+        set lines [split [memory info] "\n"]
+        lindex [lindex $lines 3] 3
+    }
+    # This test is made to stress object reference management
+    proc stress {} {
+        # A shared invalid dictinary
+        set apa {a {}b c d}
+        set bepa $apa
+        catch {dict replace $apa e f}
+        catch {dict remove  $apa c d}
+        catch {dict incr    apa  a 5}
+        catch {dict lappend apa  a 5}
+        catch {dict append  apa  a 5}
+        catch {dict set     apa  a 5}
+        catch {dict unset   apa  a}
+
+        # A shared valid dictionary, invalid incr
+        set apa {a b c d}
+        set bepa $apa
+        catch {dict incr bepa a 5}
+
+        # An error during write to an unshared object, incr
+        set apa {a 1 b 2}
+        set bepa [lrange $apa 0 end]
+        trace add variable bepa write {error hej}
+        catch {dict incr bepa a 5}
+        unset bepa
+
+        # An error during write to a shared object, incr
+        set apa {a 1 b 2}
+        set bepa $apa
+        trace add variable bepa write {error hej}
+        catch {dict incr bepa a 5}
+        unset bepa
+
+        # A shared valid dictionary, invalid lappend
+        set apa [list a {{}b} c d]
+        set bepa $apa
+        catch {dict lappend bepa a 5}
+
+        # An error during write to an unshared object, lappend
+        set apa {a 1 b 2}
+        set bepa [lrange $apa 0 end]
+        trace add variable bepa write {error hej}
+        catch {dict lappend bepa a 5}
+        unset bepa
+
+        # An error during write to a shared object, lappend
+        set apa {a 1 b 2}
+        set bepa $apa
+        trace add variable bepa write {error hej}
+        catch {dict lappend bepa a 5}
+        unset bepa
+
+        # An error during write to an unshared object, append
+        set apa {a 1 b 2}
+        set bepa [lrange $apa 0 end]
+        trace add variable bepa write {error hej}
+        catch {dict append bepa a 5}
+        unset bepa
+
+        # An error during write to a shared object, append
+        set apa {a 1 b 2}
+        set bepa $apa
+        trace add variable bepa write {error hej}
+        catch {dict append bepa a 5}
+        unset bepa
+
+        # An error during write to an unshared object, set
+        set apa {a 1 b 2}
+        set bepa [lrange $apa 0 end]
+        trace add variable bepa write {error hej}
+        catch {dict set bepa a 5}
+        unset bepa
+
+        # An error during write to a shared object, set
+        set apa {a 1 b 2}
+        set bepa $apa
+        trace add variable bepa write {error hej}
+        catch {dict set bepa a 5}
+        unset bepa
+
+        # An error during write to an unshared object, unset
+        set apa {a 1 b 2}
+        set bepa [lrange $apa 0 end]
+        trace add variable bepa write {error hej}
+        catch {dict unset bepa a}
+        unset bepa
+
+        # An error during write to a shared object, unset
+        set apa {a 1 b 2}
+        set bepa $apa
+        trace add variable bepa write {error hej}
+        catch {dict unset bepa a}
+        unset bepa
+    }
+} -constraints memory -body {
+    set end [getbytes]
+    for {set i 0} {$i < 5} {incr i} {
+        stress
+        set tmp $end
+        set end [getbytes]
+    }
+    expr {$end - $tmp}
+} -cleanup {
+    unset -nocomplain end i tmp
+    rename getbytes {}
+    rename stress {}
+} -result 0
+
 # cleanup
 ::tcltest::cleanupTests
 return