Teach fish how to push and pop blocks even in the face of no_exec. All tests finally pass.

https://github.com/fish-shell/fish-shell/issues/624

builtin.cpp

@@ -211,6 +211,10 @@ static int count_char(const wchar_t *str, wchar_t c)
 
 wcstring builtin_help_get(parser_t &parser, const wchar_t *name)
 {
+    /* This won't ever work if no_exec is set */
+    if (no_exec)
+        return wcstring();
+    
     wcstring_list_t lst;
     wcstring out;
     const wcstring name_esc = escape_string(name, 1);
@@ -3481,7 +3485,7 @@ static int builtin_end(parser_t &parser, wchar_t **argv)
            are rewinding a loop, this should be set to false, so that
            variables in the current loop scope won't die between laps.
         */
-        int kill_block = 1;
+        bool kill_block = true;
 
         switch (parser.current_block->type())
         {
@@ -3495,7 +3499,7 @@ static int builtin_end(parser_t &parser, wchar_t **argv)
                 {
                     parser.current_block->loop_status = LOOP_NORMAL;
                     parser.current_block->skip = 0;
-                    kill_block = 0;
+                    kill_block = false;
                     parser.set_pos(parser.current_block->tok_pos);
                     while_block_t *blk = static_cast<while_block_t *>(parser.current_block);
                     blk->status = WHILE_TEST_AGAIN;
@@ -3536,7 +3540,7 @@ static int builtin_end(parser_t &parser, wchar_t **argv)
                     parser.current_block->loop_status = LOOP_NORMAL;
                     parser.current_block->skip = 0;
 
-                    kill_block = 0;
+                    kill_block = false;
                     parser.set_pos(parser.current_block->tok_pos);
                 }
                 break;

exec.cpp

@@ -538,6 +538,37 @@ static bool can_use_posix_spawn_for_job(const job_t *job, const process_t *proce
     return result;
 }
 
+/* What exec does if no_exec is set. This only has to handle block pushing and popping. See #624. */
+static void exec_no_exec(parser_t &parser, const job_t *job)
+{
+    /* Hack hack hack. If this is an 'end' job, then trigger a pop. If this is a job that would create a block, trigger a push. See #624 */
+    const process_t *p = job->first_process;
+    if (p && p->type == INTERNAL_BUILTIN)
+    {
+        const wchar_t *builtin_name_cstr = p->argv0();
+        if (builtin_name_cstr != NULL)
+        {
+            const wcstring builtin_name = builtin_name_cstr;
+            if (contains(builtin_name, L"for", L"function", L"begin", L"switch"))
+            {
+                // The above builtins are the ones that produce an unbalanced block from within their function implementation
+                // This list should be maintained somewhere else
+                parser.push_block(new fake_block_t());
+            }
+            else if (builtin_name == L"end")
+            {
+                if (parser.current_block == NULL || parser.current_block->type() == TOP)
+                {
+                    fprintf(stderr, "Warning: not popping the root block\n");
+                }
+                else
+                {
+                    parser.pop_block();
+                }
+            }
+        }
+    }
+}
 
 void exec(parser_t &parser, job_t *j)
 {
@@ -559,8 +590,10 @@ void exec(parser_t &parser, job_t *j)
     CHECK(j,);
     CHECK_BLOCK();
 
-    if (no_exec)
+    if (no_exec) {
+        exec_no_exec(parser, j);
         return;
+    }
 
     sigemptyset(&chldset);
     sigaddset(&chldset, SIGCHLD);
@@ -1269,7 +1302,6 @@ void exec(parser_t &parser, job_t *j)
                     p->pid = pid;
 
                     set_child_group(j, p, 0);
-
                 }
 
                 break;

tests/top.err

@@ -1,6 +0,0 @@
-fish: Expected redirection specification, got token of type '$i'
-/usr/local/src/grissioms-fish-shell/tests/test.fish (line 51):   ../fish <$i >tmp.out ^tmp.err
-                                                                          ^
-fish: Expected redirection specification, got token of type '$i'
-/usr/local/src/grissioms-fish-shell/tests/test.fish (line 51):   ../fish <$i >tmp.out ^tmp.err
-                                                                          ^

tests/top.out

@@ -1,4 +1,5 @@
 Testing high level script functionality
+File printf.in tested ok
 File test1.in tested ok
 File test2.in tested ok
 File test3.in tested ok
@@ -7,3 +8,4 @@ File test5.in tested ok
 File test6.in tested ok
 File test7.in tested ok
 File test8.in tested ok
+File test9.in tested ok