patch 9.1.1097: --log with non-existent path causes a crash

Problem:  --log with non-existent path causes a crash
          (Ekkosun)
Solution: split initialization phase and init the execution stack
          earlier (Hirohito Higashi)

fixes: #16606
closes: #16610

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Author: h-east

Diff for: src/main.c

@@ -144,6 +144,11 @@ main
     atexit(vim_mem_profile_dump);
 #endif
 
+    /*
+     * Various initialisations #1 shared with tests.
+     */
+    common_init_1();
+
 #if defined(STARTUPTIME) || defined(FEAT_JOB_CHANNEL)
     // Need to find "--startuptime" and "--log" before actually parsing
     // arguments.
@@ -185,9 +190,9 @@ main
 #endif
 
     /*
-     * Various initialisations shared with tests.
+     * Various initialisations #2 shared with tests.
      */
-    common_init(&params);
+    common_init_2(&params);
 
 #ifdef VIMDLL
     // Check if the current executable file is for the GUI subsystem.
@@ -900,10 +905,10 @@ vim_main2(void)
 }
 
 /*
- * Initialisation shared by main() and some tests.
+ * Initialisation #1 shared by main() and some tests.
  */
     void
-common_init(mparm_T *paramp)
+common_init_1(void)
 {
     estack_init();
     cmdline_init();
@@ -925,7 +930,15 @@ common_init(mparm_T *paramp)
 	    || (NameBuff = alloc(MAXPATHL)) == NULL)
 	mch_exit(0);
     TIME_MSG("Allocated generic buffers");
+}
+
 
+/*
+ * Initialisation #2 shared by main() and some tests.
+ */
+    void
+common_init_2(mparm_T *paramp)
+{
 #ifdef NBDEBUG
     // Wait a moment for debugging NetBeans.  Must be after allocating
     // NameBuff.

Diff for: src/message_test.c

@@ -508,7 +508,8 @@ main(int argc, char **argv)
     CLEAR_FIELD(params);
     params.argc = argc;
     params.argv = argv;
-    common_init(&params);
+    common_init_1();
+    common_init_2(&params);
 
     set_option_value_give_err((char_u *)"encoding", 0, (char_u *)"utf-8", 0);
     init_chartab();

Diff for: src/proto/main.pro

@@ -1,6 +1,7 @@
 /* main.c */
 int vim_main2(void);
-void common_init(mparm_T *paramp);
+void common_init_1(void);
+void common_init_2(mparm_T *paramp);
 int is_not_a_term(void);
 int is_not_a_term_or_gui(void);
 void free_vbuf(void);

Diff for: src/testdir/test_startup.vim

@@ -740,6 +740,13 @@ func Test_log()
   call delete('Xlogfile')
 endfunc
 
+func Test_log_nonexistent()
+  " this used to crash Vim
+  CheckFeature channel
+  let result = join(systemlist(GetVimCommand() .. ' --log /X/Xlogfile -c qa!'))
+  call assert_match("E484: Can't open file", result)
+endfunc
+
 func Test_read_stdin()
   let after =<< trim [CODE]
     write Xtestout

Diff for: src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1097,
 /**/
     1096,
 /**/