diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index a3b5998271..2882d52723 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -3092,6 +3092,11 @@ static void diff_find_change_inline_diff(diff_T *dp)
   diff_T *orig_diff = curtab->tp_first_diff;
   curtab->tp_first_diff = NULL;
 
+  // diff_read() also uses curtab->tp_diffbuf to determine what's an active
+  // buffer
+  buf_T *(orig_diffbuf[DB_COUNT]);
+  memcpy(orig_diffbuf, curtab->tp_diffbuf, sizeof(orig_diffbuf));
+
   garray_T linemap[DB_COUNT];
   garray_T file1_str;
   garray_T file2_str;
@@ -3118,8 +3123,12 @@ static void diff_find_change_inline_diff(diff_T *dp)
       continue;  // skip buffer that isn't loaded
     }
     if (dp->df_count[i] == 0) {
-      continue;  // skip buffer that don't have any texts in this block
+      // skip buffers that don't have any texts in this block so we don't
+      // end up marking the entire block as modified in multi-buffer diff
+      curtab->tp_diffbuf[i] = NULL;
+      continue;
     }
+
     if (file1_idx == -1) {
       file1_idx = i;
     }
@@ -3297,7 +3306,7 @@ static void diff_find_change_inline_diff(diff_T *dp)
   for (; new_diff != NULL; new_diff = new_diff->df_next) {
     diffline_change_T change = { 0 };
     for (int i = 0; i < DB_COUNT; i++) {
-      if (new_diff->df_lnum[i] == 0) {
+      if (new_diff->df_lnum[i] <= 0) {  // should never be < 0. Checking just for safety
         continue;
       }
       linenr_T diff_lnum = new_diff->df_lnum[i] - 1;  // use zero-index
@@ -3334,6 +3343,7 @@ done:
 
   diff_clear(curtab);
   curtab->tp_first_diff = orig_diff;
+  memcpy(curtab->tp_diffbuf, orig_diffbuf, sizeof(orig_diffbuf));
 
   ga_clear(&file1_str);
   ga_clear(&file2_str);
diff --git a/test/functional/ui/diff_spec.lua b/test/functional/ui/diff_spec.lua
index 481ead8eed..a50b3d07d1 100644
--- a/test/functional/ui/diff_spec.lua
+++ b/test/functional/ui/diff_spec.lua
@@ -2801,6 +2801,32 @@ it('diff mode inline highlighting with 3 buffers', function()
   screen:expect(s6)
 end)
 
+-- oldtest: Test_diff_inline_multibuffer_empty_block()
+it('diff mode inline highlighting with multi-buffer and empty block', function()
+  write_file('Xdifile1', 'anchor1\n1234567890abcde\nanchor2')
+  write_file('Xdifile2', 'anchor1\n1234567--0abc-e\nanchor2')
+  write_file('Xdifile3', 'anchor1\nanchor2')
+  write_file('Xdifile4', 'anchor1\n1???????90abcd?\nanchor2')
+  finally(function()
+    os.remove('Xdifile1')
+    os.remove('Xdifile2')
+    os.remove('Xdifile3')
+    os.remove('Xdifile4')
+  end)
+  local screen = Screen.new(83, 20)
+  command('args Xdifile1 Xdifile2 Xdifile3 Xdifile4 | vert all | windo diffthis')
+  command('1wincmd w | set diffopt=filler,internal,inline:char')
+  screen:expect([[
+    {7:  }^anchor1           │{7:  }anchor1           │{7:  }anchor1           │{7:  }anchor1           |
+    {7:  }{4:1}{27:23456789}{4:0abc}{27:de}{4:   }│{7:  }{4:1}{27:234567--}{4:0abc}{27:-e}{4:   }│{7:  }{23:------------------}│{7:  }{4:1}{27:???????9}{4:0abc}{27:d?}{4:   }|
+    {7:  }anchor2           │{7:  }anchor2           │{7:  }anchor2           │{7:  }anchor2           |
+    {1:~                   }│{1:~                   }│{1:~                   }│{1:~                   }|*15
+    {3:Xdifile1             }{2:Xdifile2             Xdifile3             Xdifile4            }|
+                                                                                       |
+  ]])
+  n.assert_alive()
+end)
+
 it('diff mode algorithm:histogram and inline:char with long lines #34329', function()
   local screen = Screen.new(55, 20)
   exec([[
diff --git a/test/old/testdir/test_diffmode.vim b/test/old/testdir/test_diffmode.vim
index df9fb805ab..6a4c923900 100644
--- a/test/old/testdir/test_diffmode.vim
+++ b/test/old/testdir/test_diffmode.vim
@@ -2384,6 +2384,22 @@ func Test_diff_inline_multibuffer()
   call StopVimInTerminal(buf)
 endfunc
 
+" Test that when using multi-buffer diff, an empty block would be correctly
+" skipped in the result, without resulting in invalid states or crashes.
+func Test_diff_inline_multibuffer_empty_block()
+  CheckScreendump
+
+  call writefile(['anchor1', '1234567890abcde', 'anchor2'], 'Xdifile1')
+  call writefile(['anchor1', '1234567--0abc-e', 'anchor2'], 'Xdifile2')
+  call writefile(['anchor1', 'anchor2'], 'Xdifile3')
+  call writefile(['anchor1', '1???????90abcd?', 'anchor2'], 'Xdifile4')
+
+  let buf = RunVimInTerminal('-d Xdifile1 Xdifile2 Xdifile3 Xdifile4', {})
+  call VerifyInternal(buf, "Test_diff_inline_multibuffer_empty_block_01", " diffopt+=inline:char")
+
+  call StopVimInTerminal(buf)
+endfunc
+
 func Test_diffget_diffput_linematch()
   CheckScreendump
   call delete('.Xdifile1.swp')