Fix problems with break and continue in for-step clauses, triggered by reporting

of Coverity CID 1251203. Some of these were originally bugs in Tcl 8.0.

3 files changed, 202 insertions, 27 deletions

diff --git a/generic/tclCompile.c b/generic/tclCompile.c
index 824276c..f62ec14 100644
--- a/generic/tclCompile.c
+++ b/generic/tclCompile.c
@@ -4083,16 +4083,6 @@ TclEmitInvoke(
      * calls from inside a [for] increment clause).
      */
 
-    rangePtr = TclGetInnermostExceptionRange(envPtr, TCL_BREAK, &auxBreakPtr);
-    if (rangePtr == NULL || rangePtr->type != LOOP_EXCEPTION_RANGE) {
-	auxBreakPtr = NULL;
-    } else if (auxBreakPtr->stackDepth == envPtr->currStackDepth-wordCount
-	    && auxBreakPtr->expandTarget == envPtr->expandCount-expandCount) {
-	auxBreakPtr = NULL;
-    } else {
-	breakRange = auxBreakPtr - envPtr->exceptAuxArrayPtr;
-    }
-
     rangePtr = TclGetInnermostExceptionRange(envPtr, TCL_CONTINUE,
 	    &auxContinuePtr);
     if (rangePtr == NULL || rangePtr->type != LOOP_EXCEPTION_RANGE) {
@@ -4101,7 +4091,18 @@ TclEmitInvoke(
 	    && auxContinuePtr->expandTarget == envPtr->expandCount-expandCount) {
 	auxContinuePtr = NULL;
     } else {
-	continueRange = auxBreakPtr - envPtr->exceptAuxArrayPtr;
+	continueRange = auxContinuePtr - envPtr->exceptAuxArrayPtr;
+    }
+
+    rangePtr = TclGetInnermostExceptionRange(envPtr, TCL_BREAK, &auxBreakPtr);
+    if (rangePtr == NULL || rangePtr->type != LOOP_EXCEPTION_RANGE) {
+	auxBreakPtr = NULL;
+    } else if (auxContinuePtr == NULL
+	    && auxBreakPtr->stackDepth == envPtr->currStackDepth-wordCount
+	    && auxBreakPtr->expandTarget == envPtr->expandCount-expandCount) {
+	auxBreakPtr = NULL;
+    } else {
+	breakRange = auxBreakPtr - envPtr->exceptAuxArrayPtr;
     }
 
     if (auxBreakPtr != NULL || auxContinuePtr != NULL) {
diff --git a/generic/tclExecute.c b/generic/tclExecute.c
index b3f0c4d..8ada6d2 100644
--- a/generic/tclExecute.c
+++ b/generic/tclExecute.c
@@ -758,7 +758,7 @@ static Tcl_Obj *	ExecuteExtendedUnaryMathOp(int opcode,
 			    Tcl_Obj *valuePtr);
 static void		FreeExprCodeInternalRep(Tcl_Obj *objPtr);
 static ExceptionRange *	GetExceptRangeForPc(const unsigned char *pc,
-			    int catchOnly, ByteCode *codePtr);
+			    int searchMode, ByteCode *codePtr);
 static const char *	GetSrcInfoForPc(const unsigned char *pc,
 			    ByteCode *codePtr, int *lengthPtr,
 			    const unsigned char **pcBeg, int *cmdIdxPtr);
@@ -7955,7 +7955,7 @@ TEBCresume(
 	}
 #endif
 	if ((result == TCL_CONTINUE) || (result == TCL_BREAK)) {
-	    rangePtr = GetExceptRangeForPc(pc, /*catchOnly*/ 0, codePtr);
+	    rangePtr = GetExceptRangeForPc(pc, result, codePtr);
 	    if (rangePtr == NULL) {
 		TRACE_APPEND(("no encl. loop or catch, returning %s\n",
 			StringForResultCode(result)));
@@ -8116,7 +8116,7 @@ TEBCresume(
 #endif
 	    goto abnormalReturn;
 	}
-	rangePtr = GetExceptRangeForPc(pc, /*catchOnly*/ 1, codePtr);
+	rangePtr = GetExceptRangeForPc(pc, TCL_ERROR, codePtr);
 	if (rangePtr == NULL) {
 	    /*
 	     * This is only possible when compiling a [catch] that sends its
@@ -10112,13 +10112,14 @@ GetSrcInfoForPc(
  *	ExceptionRange.
  *
  * Results:
- *	In the normal case, catchOnly is 0 (false) and this procedure returns
- *	a pointer to the most closely enclosing ExceptionRange structure
- *	regardless of whether it is a loop or catch exception range. This is
- *	appropriate when processing a TCL_BREAK or TCL_CONTINUE, which will be
- *	"handled" either by a loop exception range or a closer catch range. If
- *	catchOnly is nonzero, this procedure ignores loop exception ranges and
- *	returns a pointer to the closest catch range. If no matching
+ *	If the searchMode is TCL_ERROR, this procedure ignores loop exception
+ *	ranges and returns a pointer to the closest catch range. If the
+ *	searchMode is TCL_BREAK, this procedure returns a pointer to the most
+ *	closely enclosing ExceptionRange regardless of whether it is a loop or
+ *	catch exception range. If the searchMode is TCL_CONTINUE, this
+ *	procedure returns a pointer to the most closely enclosing
+ *	ExceptionRange (of any type) skipping only loop exception ranges if
+ *	they don't have a sensible continueOffset defined. If no matching
  *	ExceptionRange is found that encloses pc, a NULL is returned.
  *
  * Side effects:
@@ -10129,14 +10130,16 @@ GetSrcInfoForPc(
 
 static ExceptionRange *
 GetExceptRangeForPc(
-    const unsigned char *pc, /* The program counter value for which to
+    const unsigned char *pc,	/* The program counter value for which to
 				 * search for a closest enclosing exception
 				 * range. This points to a bytecode
 				 * instruction in codePtr's code. */
-    int catchOnly,		/* If 0, consider either loop or catch
-				 * ExceptionRanges in search. If nonzero
+    int searchMode,		/* If TCL_BREAK, consider either loop or catch
+				 * ExceptionRanges in search. If TCL_ERROR
 				 * consider only catch ranges (and ignore any
-				 * closer loop ranges). */
+				 * closer loop ranges). If TCL_CONTINUE, look
+				 * for loop ranges that define a continue
+				 * point or a catch range. */
     ByteCode *codePtr)		/* Points to the ByteCode in which to search
 				 * for the enclosing ExceptionRange. */
 {
@@ -10162,8 +10165,13 @@ GetExceptRangeForPc(
 	start = rangePtr->codeOffset;
 	if ((start <= pcOffset) &&
 		(pcOffset < (start + rangePtr->numCodeBytes))) {
-	    if ((!catchOnly)
-		    || (rangePtr->type == CATCH_EXCEPTION_RANGE)) {
+	    if (rangePtr->type == CATCH_EXCEPTION_RANGE) {
+		return rangePtr;
+	    }
+	    if (searchMode == TCL_BREAK) {
+		return rangePtr;
+	    }
+	    if (searchMode == TCL_CONTINUE && rangePtr->continueOffset != -1){
 		return rangePtr;
 	    }
 	}
diff --git a/tests/for.test b/tests/for.test
index 8abd270..1a65274 100644
--- a/tests/for.test
+++ b/tests/for.test
@@ -1184,6 +1184,172 @@ test for-7.24 {Bug 3614226: ensure that continue from expanded command only clea
 	expr {$end - $tmp}
     }} {return -level 0 -code continue}
 } 0
+
+test for-8.0 {Coverity CID 1251203: break vs continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i; list a [eval {}]} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {6 5 3}
+test for-8.1 {Coverity CID 1251203: break vs continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i;list a [eval break]} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {2 1 3}
+test for-8.2 {Coverity CID 1251203: break vs continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i;list a [eval continue]} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {1 1 3}
+test for-8.3 {break in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i; break} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {2 1 3}
+test for-8.4 {continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i; continue} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {1 1 3}
+test for-8.5 {break in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i; list a [break]} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {2 1 3}
+test for-8.6 {continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i; list a [continue]} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {1 1 3}
+test for-8.7 {break in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i;eval break} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {2 1 3}
+test for-8.8 {continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    list a [\
+	    for {set i 0} {$i < 5} {incr i;eval continue} {
+		incr j
+	    }]
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {1 1 3}
+test for-8.9 {break in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    for {set i 0} {$i < 5} {incr i;eval break} {
+		incr j
+	    }
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {2 1 3}
+test for-8.10 {continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    for {set i 0} {$i < 5} {incr i;eval continue} {
+		incr j
+	    }
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {1 1 3}
+test for-8.11 {break in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    for {set i 0} {$i < 5} {incr i;break} {
+		incr j
+	    }
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {2 1 3}
+test for-8.12 {continue in for-step clause} {
+    apply {{} {
+	for {set k 0} {$k < 3} {incr k} {
+	    set j 0
+	    for {set i 0} {$i < 5} {incr i;continue} {
+		incr j
+	    }
+	    incr i
+	}
+	list $i $j $k
+    }}
+} {1 1 3}
 
 # cleanup
 ::tcltest::cleanupTests