zlib: Fix arg error checking

It is wrong to call Jim_WrongNumArgs() with argc == 0.
Instead -1 should be returned from the subcmd function to display the standard error message.

Add a --maintainer check for this condition in Jim_WrongNumArgs() and fix the zlib unit tests.

Signed-off-by: Steve Bennett <steveb@workware.net.au>

3 files changed, 18 insertions, 20 deletions

diff --git a/jim-zlib.c b/jim-zlib.c
index ea8b6dc..6965d79 100644
--- a/jim-zlib.c
+++ b/jim-zlib.c
@@ -132,19 +132,16 @@ static int Jim_Gzip(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
     if (argc == 3) {
         if (!Jim_CompareStringImmediate(interp, argv[1], "-level")) {
-            Jim_WrongNumArgs(interp, 0, argv, "data ?-level level?");
-            return JIM_ERR;
+            return -1;
         }
 
         if (Jim_GetLong(interp, argv[2], &level) != JIM_OK) {
-            Jim_WrongNumArgs(interp, 0, argv, "data ?-level level?");
-            return JIM_ERR;
+            return -1;
         }
 
     }
     else if (argc != 1) {
-        Jim_WrongNumArgs(interp, 0, argv, "data ?-level level?");
-        return JIM_ERR;
+        return -1;
     }
 
     in = Jim_GetString(argv[0], &len);
@@ -240,19 +237,16 @@ static int Jim_Gunzip(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 
     if (argc == 3) {
         if (!Jim_CompareStringImmediate(interp, argv[1], "-buffersize")) {
-            Jim_WrongNumArgs(interp, 0, argv, "data ?-buffersize size?");
-            return JIM_ERR;
+            return -1;
         }
 
         if (Jim_GetLong(interp, argv[2], &bufsiz) != JIM_OK) {
-            Jim_WrongNumArgs(interp, 0, argv, "data ?-buffersize size?");
-            return JIM_ERR;
+            return -1;
         }
 
     }
     else if (argc != 1) {
-        Jim_WrongNumArgs(interp, 0, argv, "data ?-buffersize size?");
-        return JIM_ERR;
+        return -1;
     }
 
     in = Jim_GetString(argv[0], &len);
diff --git a/jim.c b/jim.c
index d7d5f0e..00c6c0c 100644
--- a/jim.c
+++ b/jim.c
@@ -11363,7 +11363,11 @@ int Jim_SubstObj(Jim_Interp *interp, Jim_Obj *substObjPtr, Jim_Obj **resObjPtrPt
 void Jim_WrongNumArgs(Jim_Interp *interp, int argc, Jim_Obj *const *argv, const char *msg)
 {
     Jim_Obj *objPtr;
-    Jim_Obj *listObjPtr = Jim_NewListObj(interp, argv, argc);
+    Jim_Obj *listObjPtr;
+
+    JimPanic((argc == 0, "Jim_WrongNumArgs() called with argc=0"));
+
+    listObjPtr = Jim_NewListObj(interp, argv, argc);
 
     if (*msg) {
         Jim_ListAppendElement(interp, listObjPtr, Jim_NewStringObj(interp, msg, -1));
diff --git a/tests/zlib.test b/tests/zlib.test
index 3153ab7..f2b4a36 100644
--- a/tests/zlib.test
+++ b/tests/zlib.test
@@ -69,19 +69,19 @@ test zlib-3.2 {zlib gunzip usage 2} -returnCodes error -body {
 
 test zlib-3.3 {zlib gunzip usage 3} -returnCodes error -body {
     zlib gunzip aaa 4
-} -result {wrong # args: should be "data ?-buffersize size?"}
+} -result {wrong # args: should be "zlib gunzip data ?-buffersize size?"}
 
 test zlib-3.4 {zlib gunzip usage 4} -returnCodes error -body {
     zlib gunzip aaa -buffersize
-} -result {wrong # args: should be "data ?-buffersize size?"}
+} -result {wrong # args: should be "zlib gunzip data ?-buffersize size?"}
 
 test zlib-3.5 {zlib gunzip usage 5} -returnCodes error -body {
     zlib gunzip aaa -buffersize a
-} -result {wrong # args: should be "data ?-buffersize size?"}
+} -result {wrong # args: should be "zlib gunzip data ?-buffersize size?"}
 
 test zlib-3.6 {zlib gunzip usage 5} -returnCodes error -body {
     zlib gunzip aaa -buffersize a
-} -result {wrong # args: should be "data ?-buffersize size?"}
+} -result {wrong # args: should be "zlib gunzip data ?-buffersize size?"}
 
 test zlib-3.7 {zlib gunzip usage 6} -returnCodes error -body {
     zlib gunzip aaa -buffersize 0
@@ -93,15 +93,15 @@ test zlib-3.8 {zlib gzip usage 1} -returnCodes error -body {
 
 test zlib-3.9 {zlib gzip usage 2} -returnCodes error -body {
     zlib gzip aa 9
-} -result {wrong # args: should be "data ?-level level?"}
+} -result {wrong # args: should be "zlib gzip data ?-level level?"}
 
 test zlib-3.10 {zlib gzip usage 3} -returnCodes error -body {
     zlib gzip -level a
-} -result {wrong # args: should be "data ?-level level?"}
+} -result {wrong # args: should be "zlib gzip data ?-level level?"}
 
 test zlib-3.11 {zlib gzip usage 4} -returnCodes error -body {
     zlib gzip -level 9 a
-} -result {wrong # args: should be "data ?-level level?"}
+} -result {wrong # args: should be "zlib gzip data ?-level level?"}
 
 test zlib-4.1 {zlib gzip/gunzip} {
     zlib gunzip [zlib gzip abcdefghijklm]