patch 8.2.4951: smart indenting done when not enabled

Problem:    Smart indenting done when not enabled.
Solution:   Check option values before setting can_si. (closes #10420)

src/change.c

@@ -1392,14 +1392,7 @@ open_line(
     int		do_cindent;
 #endif
 #ifdef FEAT_SMARTINDENT
-    int		do_si = (!p_paste && curbuf->b_p_si
-# ifdef FEAT_CINDENT
-					&& !curbuf->b_p_cin
-# endif
-# ifdef FEAT_EVAL
-					&& *curbuf->b_p_inde == NUL
-# endif
-			);
+    int		do_si = may_do_si();
     int		no_si = FALSE;		// reset did_si afterwards
     int		first_char = NUL;	// init for GCC
 #endif

src/edit.c

@@ -1295,7 +1295,7 @@ edit(
 #endif
 	    compl_busy = FALSE;
 #ifdef FEAT_SMARTINDENT
-	    can_si = TRUE; // allow smartindenting
+	    can_si = may_do_si(); // allow smartindenting
 #endif
 	    break;
 

src/indent.c

@@ -1168,6 +1168,22 @@ preprocs_left(void)
 #endif
 
 #ifdef FEAT_SMARTINDENT
+/*
+ * Return TRUE if the conditions are OK for smart indenting.
+ */
+    int
+may_do_si()
+{
+    return curbuf->b_p_si
+# ifdef FEAT_CINDENT
+	&& !curbuf->b_p_cin
+# endif
+# ifdef FEAT_EVAL
+	&& *curbuf->b_p_inde == NUL
+# endif
+	&& !p_paste;
+}
+
 /*
  * Try to do some very smart auto-indenting.
  * Used when inserting a "normal" character.
@@ -1235,7 +1251,7 @@ ins_try_si(int c)
     }
 
     // set indent of '#' always to 0
-    if (curwin->w_cursor.col > 0 && can_si && c == '#')
+    if (curwin->w_cursor.col > 0 && can_si && c == '#' && inindent(0))
     {
 	// remember current indent for next line
 	old_indent = get_indent();

src/ops.c

@@ -1718,12 +1718,7 @@ op_change(oparg_T *oap)
     {
 	l = 0;
 #ifdef FEAT_SMARTINDENT
-	if (!p_paste && curbuf->b_p_si
-# ifdef FEAT_CINDENT
-		&& !curbuf->b_p_cin
-# endif
-		)
-	    can_si = TRUE;	// It's like opening a new line, do si
+	can_si = may_do_si();	// Like opening a new line, do smart indent
 #endif
     }
 

src/proto/indent.pro

@@ -23,6 +23,7 @@ int get_breakindent_win(win_T *wp, char_u *line);
 int inindent(int extra);
 void op_reindent(oparg_T *oap, int (*how)(void));
 int preprocs_left(void);
+int may_do_si(void);
 void ins_try_si(int c);
 void change_indent(int type, int amount, int round, int replaced, int call_changed_bytes);
 int copy_indent(int size, char_u *src);

src/testdir/test_smartindent.vim

@@ -134,4 +134,21 @@ func Test_si_with_paste()
   bw!
 endfunc
 
+func Test_si_after_completion()
+  new
+  setlocal ai smartindent indentexpr=
+  call setline(1, 'foo foot')
+  call feedkeys("o  f\<C-X>\<C-N>#", 'tx')
+  call assert_equal('  foo#', getline(2))
+  bwipe!
+endfunc
+
+func Test_no_si_after_completion()
+  new
+  call setline(1, 'foo foot')
+  call feedkeys("o  f\<C-X>\<C-N>#", 'tx')
+  call assert_equal('  foo#', getline(2))
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4951,
 /**/
     4950,
 /**/