patch 9.0.1734: :runtime completion fails for multiple args

Problem: :runtime completion fails for multiple args
Solution: Make it work

closes: #12616

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
diff --git a/src/scriptfile.c b/src/scriptfile.c
index 37d57e5..2aca346 100644
--- a/src/scriptfile.c
+++ b/src/scriptfile.c
@@ -289,6 +289,15 @@
     char_u  *p = skiptowhite(arg);
     runtime_expand_flags
 	= *p != NUL ? get_runtime_cmd_flags(&arg, p - arg) : 0;
+    // Skip to the last argument.
+    while (*(p = skiptowhite_esc(arg)) != NUL)
+    {
+	if (runtime_expand_flags == 0)
+	    // When there are multiple arguments and [where] is not specified,
+	    // use an unrelated non-zero flag to avoid expanding [where].
+	    runtime_expand_flags = DIP_ALL;
+	arg = skipwhite(p);
+    }
     xp->xp_context = EXPAND_RUNTIME;
     xp->xp_pattern = arg;
 }
diff --git a/src/testdir/test_packadd.vim b/src/testdir/test_packadd.vim
index 33dcfe0..eab710d 100644
--- a/src/testdir/test_packadd.vim
+++ b/src/testdir/test_packadd.vim
@@ -433,9 +433,9 @@
   call writefile([], optdir . '/../Aunrelated')
   exe 'set rtp=' . &packpath . '/runtime'
 
-  func Check_runtime_completion(arg, arg1, res)
+  func Check_runtime_completion(arg, arg_prev, res)
     call feedkeys(':runtime ' .. a:arg .. "\<C-A>\<C-B>\"\<CR>", 'xt')
-    call assert_equal('"runtime ' .. a:arg1 .. join(a:res), @:)
+    call assert_equal('"runtime ' .. a:arg_prev .. join(a:res), @:)
     call assert_equal(a:res, getcompletion(a:arg, 'runtime'))
   endfunc
 
@@ -449,39 +449,70 @@
         \ ['PACK'])
   call Check_runtime_completion('A', '',
         \ ['Aextra/', 'Arunfoo.vim', 'ALL'])
+  call Check_runtime_completion('Other.vim ', 'Other.vim ',
+        \ ['Aextra/', 'Arunfoo.vim'])
   call Check_runtime_completion('Aextra/', '',
         \ ['Aextra/Arunbar.vim', 'Aextra/Arunbaz/'])
+  call Check_runtime_completion('Other.vim Aextra/', 'Other.vim ',
+        \ ['Aextra/Arunbar.vim', 'Aextra/Arunbaz/'])
 
   call Check_runtime_completion('START ', 'START ',
         \ ['Aextra/', 'Astartfoo.vim'])
+  call Check_runtime_completion('START Other.vim ', 'START Other.vim ',
+        \ ['Aextra/', 'Astartfoo.vim'])
   call Check_runtime_completion('START A', 'START ',
         \ ['Aextra/', 'Astartfoo.vim'])
+  call Check_runtime_completion('START Other.vim A', 'START Other.vim ',
+        \ ['Aextra/', 'Astartfoo.vim'])
   call Check_runtime_completion('START Aextra/', 'START ',
         \ ['Aextra/Astartbar.vim', 'Aextra/Astartbaz/'])
+  call Check_runtime_completion('START Other.vim Aextra/', 'START Other.vim ',
+        \ ['Aextra/Astartbar.vim', 'Aextra/Astartbaz/'])
 
   call Check_runtime_completion('OPT ', 'OPT ',
         \ ['Aextra/', 'Aoptfoo.vim'])
+  call Check_runtime_completion('OPT Other.vim ', 'OPT Other.vim ',
+        \ ['Aextra/', 'Aoptfoo.vim'])
   call Check_runtime_completion('OPT A', 'OPT ',
         \ ['Aextra/', 'Aoptfoo.vim'])
+  call Check_runtime_completion('OPT Other.vim A', 'OPT Other.vim ',
+        \ ['Aextra/', 'Aoptfoo.vim'])
   call Check_runtime_completion('OPT Aextra/', 'OPT ',
         \ ['Aextra/Aoptbar.vim', 'Aextra/Aoptbaz/'])
+  call Check_runtime_completion('OPT Other.vim Aextra/', 'OPT Other.vim ',
+        \ ['Aextra/Aoptbar.vim', 'Aextra/Aoptbaz/'])
 
   call Check_runtime_completion('PACK ', 'PACK ',
         \ ['Aextra/', 'Aoptfoo.vim', 'Astartfoo.vim'])
+  call Check_runtime_completion('PACK Other.vim ', 'PACK Other.vim ',
+        \ ['Aextra/', 'Aoptfoo.vim', 'Astartfoo.vim'])
   call Check_runtime_completion('PACK A', 'PACK ',
         \ ['Aextra/', 'Aoptfoo.vim', 'Astartfoo.vim'])
+  call Check_runtime_completion('PACK Other.vim A', 'PACK Other.vim ',
+        \ ['Aextra/', 'Aoptfoo.vim', 'Astartfoo.vim'])
   call Check_runtime_completion('PACK Aextra/', 'PACK ',
         \ ['Aextra/Aoptbar.vim', 'Aextra/Aoptbaz/',
         \ 'Aextra/Astartbar.vim', 'Aextra/Astartbaz/'])
+  call Check_runtime_completion('PACK Other.vim Aextra/', 'PACK Other.vim ',
+        \ ['Aextra/Aoptbar.vim', 'Aextra/Aoptbaz/',
+        \ 'Aextra/Astartbar.vim', 'Aextra/Astartbaz/'])
 
   call Check_runtime_completion('ALL ', 'ALL ',
         \ ['Aextra/', 'Aoptfoo.vim', 'Arunfoo.vim', 'Astartfoo.vim'])
+  call Check_runtime_completion('ALL Other.vim ', 'ALL Other.vim ',
+        \ ['Aextra/', 'Aoptfoo.vim', 'Arunfoo.vim', 'Astartfoo.vim'])
   call Check_runtime_completion('ALL A', 'ALL ',
         \ ['Aextra/', 'Aoptfoo.vim', 'Arunfoo.vim', 'Astartfoo.vim'])
+  call Check_runtime_completion('ALL Other.vim A', 'ALL Other.vim ',
+        \ ['Aextra/', 'Aoptfoo.vim', 'Arunfoo.vim', 'Astartfoo.vim'])
   call Check_runtime_completion('ALL Aextra/', 'ALL ',
         \ ['Aextra/Aoptbar.vim', 'Aextra/Aoptbaz/',
         \ 'Aextra/Arunbar.vim', 'Aextra/Arunbaz/',
         \ 'Aextra/Astartbar.vim', 'Aextra/Astartbaz/'])
+  call Check_runtime_completion('ALL Other.vim Aextra/', 'ALL Other.vim ',
+        \ ['Aextra/Aoptbar.vim', 'Aextra/Aoptbaz/',
+        \ 'Aextra/Arunbar.vim', 'Aextra/Arunbaz/',
+        \ 'Aextra/Astartbar.vim', 'Aextra/Astartbaz/'])
 
   delfunc Check_runtime_completion
 endfunc
diff --git a/src/version.c b/src/version.c
index 539b389..ba42318 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1734,
+/**/
     1733,
 /**/
     1732,