fixes #14511 [backport:1.4] (#18732)

* fixes #14511 [backport:1.4]

Signed-off-by: Dankr4d <dude569@freenet.de>

* Replaced fix with code from alaviss, for better readability, with small
changes.

Signed-off-by: Dankr4d <dude569@freenet.de>

* - Specified output in test.

Signed-off-by: Dankr4d <dude569@freenet.de>

* Replaced case in nnkRecCase with a simpler version, which just adds the
last son.

Signed-off-by: Dankr4d <dude569@freenet.de>

* Update tests/macros/t14511.nim

* Update tests/macros/t14511.nim

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

2 files changed, 64 insertions, 11 deletions

diff --git a/lib/core/macros.nim b/lib/core/macros.nim
index 645f5067a..806ea7e31 100644
--- a/lib/core/macros.nim
+++ b/lib/core/macros.nim
@@ -1541,18 +1541,17 @@ proc customPragmaNode(n: NimNode): NimNode =
         for i in 0..<identDefsStack.len: identDefsStack[i] = obj[2][i]
         while identDefsStack.len > 0:
           var identDefs = identDefsStack.pop()
-          if identDefs.kind == nnkRecCase:
-            identDefsStack.add(identDefs[0])
-            for i in 1..<identDefs.len:
-              let varNode = identDefs[i]
-              # if it is and empty branch, skip
-              if varNode[0].kind == nnkNilLit: continue
-              if varNode[1].kind == nnkIdentDefs:
-                identDefsStack.add(varNode[1])
-              else: # nnkRecList
-                for j in 0 ..< varNode[1].len:
-                  identDefsStack.add(varNode[1][j])
 
+          case identDefs.kind
+          of nnkRecList:
+            for child in identDefs.children:
+              identDefsStack.add(child)
+          of nnkRecCase:
+            # Add condition definition
+            identDefsStack.add(identDefs[0])
+            # Add branches
+            for i in 1 ..< identDefs.len:
+              identDefsStack.add(identDefs[i].last)
           else:
             for i in 0 .. identDefs.len - 3:
               let varNode = identDefs[i]
diff --git a/tests/macros/t14511.nim b/tests/macros/t14511.nim
new file mode 100644
index 000000000..f3b1e2894
--- /dev/null
+++ b/tests/macros/t14511.nim
@@ -0,0 +1,54 @@
+discard """
+  output: "true\n(y: XInt, a: 5)\n(y: XString, b: \"abc\")"
+"""
+
+import macros
+
+block TEST_1:
+  # https://github.com/nim-lang/Nim/issues/14511
+
+  template myPragma() {.pragma.}
+
+  type
+    XType = enum
+      XInt,
+      XString,
+      XUnused
+    X = object
+      case y {.myPragma.}: XType
+        of XInt, XUnused:
+          a: int
+        else: # <-- Else case caused the "Error: index 1 not in 0 .. 0" error
+          b: string
+
+  var x: X = X(y: XInt, a: 5)
+  echo x.y.hasCustomPragma(myPragma)
+  echo x
+  echo X(y: XString, b: "abc")
+
+
+block TEST_2:
+  template myDevice(val: string) {.pragma.}
+  template myKey(val: string) {.pragma.}
+  template myMouse(val: string) {.pragma.}
+
+  type
+    Device {.pure.} = enum Keyboard, Mouse
+    Key = enum Key1, Key2
+    Mouse = enum Mouse1, Mouse2
+
+  type
+    Obj = object of RootObj
+      case device {.myDevice: "MyDevicePragmaStr".}: Device
+      of Device.Keyboard:
+        key {.myKey: "MyKeyPragmaStr".}: Key
+      else: # <-- Else case caused the "Error: index 1 not in 0 .. 0" error
+        mouse {.myMouse: "MyMousePragmaStr".}: Mouse
+
+  var obj: Obj
+  assert obj.device.hasCustomPragma(myDevice) == true
+  assert obj.key.hasCustomPragma(myKey) == true
+  assert obj.mouse.hasCustomPragma(myMouse) == true
+  assert obj.device.getCustomPragmaVal(myDevice) == "MyDevicePragmaStr"
+  assert obj.key.getCustomPragmaVal(myKey) == "MyKeyPragmaStr"
+  assert obj.mouse.getCustomPragmaVal(myMouse) == "MyMousePragmaStr"
\ No newline at end of file