[cdv] Fix test of size limit reached on crash dump

This test failed every now and then since the selected max size could
be greater than the actual size of the dump - so the dump was not
truncated. This is now corrected.

1 files changed, 23 insertions, 7 deletions

diff --git a/lib/observer/test/crashdump_viewer_SUITE.erl b/lib/observer/test/crashdump_viewer_SUITE.erl
index 02adfb6508..29b9e406ae 100644
--- a/lib/observer/test/crashdump_viewer_SUITE.erl
+++ b/lib/observer/test/crashdump_viewer_SUITE.erl
@@ -649,13 +649,7 @@ do_create_dumps(DataDir,Rel) ->
 	current ->
 	    CD3 = dump_with_args(DataDir,Rel,"instr","+Mim true"),
 	    CD4 = dump_with_strange_module_name(DataDir,Rel,"strangemodname"),
-	    Tmp = dump_with_args(DataDir,Rel,"trunc_bytes",""),
-            {ok,#file_info{size=Max}} = file:read_file_info(Tmp),
-            ok = file:delete(Tmp),
-            Bytes = max(15,rand:uniform(Max)),
-            CD5 = dump_with_args(DataDir,Rel,"trunc_bytes",
-                                 "-env ERL_CRASH_DUMP_BYTES " ++
-                                     integer_to_list(Bytes)),
+            CD5 = dump_with_size_limit_reached(DataDir,Rel,"trunc_bytes"),
             CD6 = dump_with_unicode_atoms(DataDir,Rel,"unicode"),
             CD7 = dump_with_maps(DataDir,Rel,"maps"),
             TruncatedDumps = truncate_dump(CD1),
@@ -768,6 +762,28 @@ dump_with_strange_module_name(DataDir,Rel,DumpName) ->
     ?t:stop_node(n1),
     CD.
 
+dump_with_size_limit_reached(DataDir,Rel,DumpName) ->
+    Tmp = dump_with_args(DataDir,Rel,DumpName,""),
+    {ok,#file_info{size=Max}} = file:read_file_info(Tmp),
+    ok = file:delete(Tmp),
+    dump_with_size_limit_reached(DataDir,Rel,DumpName,Max).
+
+dump_with_size_limit_reached(DataDir,Rel,DumpName,Max) ->
+    Bytes = max(15,rand:uniform(Max)),
+    CD = dump_with_args(DataDir,Rel,DumpName,
+                        "-env ERL_CRASH_DUMP_BYTES " ++
+                            integer_to_list(Bytes)),
+    {ok,#file_info{size=Size}} = file:read_file_info(CD),
+    if Size < Bytes ->
+            %% This means that the dump was actually smaller than the
+            %% randomly selected truncation size, so we'll just do it
+            %% again with a smaller numer
+            ok = file:delete(CD),
+            dump_with_size_limit_reached(DataDir,Rel,DumpName,Size-3);
+       true ->
+            CD
+    end.
+
 dump_with_unicode_atoms(DataDir,Rel,DumpName) ->
     Opt = rel_opt(Rel),
     Pz = "-pz \"" ++ filename:dirname(code:which(?MODULE)) ++ "\"",