Merge pull request #29272 from luukvbaal/signcol

fix(column): clamp line number for legacy signs

src/nvim/sign.c

@@ -126,8 +126,8 @@ static void buf_set_sign(buf_T *buf, uint32_t *id, char *group, int prio, linenr
                          | (has_hl ? MT_FLAG_DECOR_SIGNHL : 0);
 
   DecorInline decor = { .ext = true, .data.ext = { .vt = NULL, .sh_idx = decor_put_sh(sign) } };
-  extmark_set(buf, ns, id, lnum - 1, 0, -1, -1, decor, decor_flags, true,
-              false, true, true, NULL);
+  extmark_set(buf, ns, id, MIN(buf->b_ml.ml_line_count, lnum) - 1, 0, -1, -1,
+              decor, decor_flags, true, false, true, true, NULL);
 }
 
 /// For an existing, placed sign with "id", modify the sign, group or priority.

test/functional/ui/sign_spec.lua

@@ -577,4 +577,34 @@ describe('Signs', function()
     ]])
     eq({}, eval('sign_getdefined()'))
   end)
+
+  it('no crash when unplacing signs beyond end of buffer', function()
+    exec([[
+      sign define S1 text=S1
+      sign define S2 text=S2
+      sign place 1 line=8 name=S1
+      sign place 2 line=9 name=S2
+    ]])
+    -- Now placed at end of buffer
+    local s1 = {
+      grid = [[
+        S2^                                                   |
+        {0:~                                                    }|*12
+                                                             |
+      ]],
+    }
+    screen:expect(s1)
+    -- Signcolumn tracking used to not count signs placed beyond end of buffer here
+    exec('set signcolumn=auto:9')
+    screen:expect({
+      grid = [[
+        S2S1^                                                 |
+        {0:~                                                    }|*12
+                                                             |
+      ]],
+    })
+    -- Unplacing the sign does not crash by decrementing tracked signs below zero
+    exec('sign unplace 1')
+    screen:expect(s1)
+  end)
 end)

test/old/testdir/test_signs.vim

@@ -89,8 +89,9 @@ func Test_sign()
   " Place a sign without specifying the filename or buffer
   sign place 77 line=9 name=Sign2
   let a=execute('sign place')
+  " Nvim: sign line clamped to buffer length
   call assert_equal("\n--- Signs ---\nSigns for [NULL]:\n" .
-		\ "    line=9  id=77  name=Sign2  priority=10\n", a)
+		\ "    line=4  id=77  name=Sign2  priority=10\n", a)
   sign unplace *
 
   " Check :jump with file=...
@@ -799,10 +800,11 @@ func Test_sign_group()
   set buftype=nofile
   sign place 25 line=76 name=sign1 priority=99 file=foo
   let a = execute('sign place')
+  " Nvim: sign line clamped to buffer length
   call assert_equal("\n--- Signs ---\nSigns for Xsign:\n" .
 	      \ "    line=10  id=5  name=sign1  priority=10\n" .
 	      \ "Signs for foo:\n" .
-	      \ "    line=76  id=25  name=sign1  priority=99\n", a)
+	      \ "    line=1  id=25  name=sign1  priority=99\n", a)
   close
   bwipe foo