Render bug: if expression with statement list expression as condition (#8375)

* Fixes #8348

compiler/parser.nim

@@ -568,6 +568,7 @@ proc parsePar(p: var TParser): PNode =
   result = newNodeP(nkPar, p)
   getTok(p)
   optInd(p, result)
+  flexComment(p, result)
   if p.tok.tokType in {tkDiscard, tkInclude, tkIf, tkWhile, tkCase,
                        tkTry, tkDefer, tkFinally, tkExcept, tkFor, tkBlock,
                        tkConst, tkLet, tkWhen, tkVar,

compiler/renderer.nim

@@ -634,9 +634,16 @@ proc gstmts(g: var TSrcGen, n: PNode, c: TContext, doIndent=true) =
     optNL(g)
 
 
+proc gcond(g: var TSrcGen, n: PNode) =
+  if n.kind == nkStmtListExpr:
+    put(g, tkParLe, "(")
+  gsub(g, n)  
+  if n.kind == nkStmtListExpr:
+    put(g, tkParRi, ")")
+
 proc gif(g: var TSrcGen, n: PNode) =
   var c: TContext
-  gsub(g, n.sons[0].sons[0])
+  gcond(g, n.sons[0].sons[0])
   initContext(c)
   putWithSpace(g, tkColon, ":")
   if longMode(g, n) or (lsub(g, n.sons[0].sons[1]) + g.lineLen > MaxLineLen):
@@ -651,7 +658,7 @@ proc gif(g: var TSrcGen, n: PNode) =
 proc gwhile(g: var TSrcGen, n: PNode) =
   var c: TContext
   putWithSpace(g, tkWhile, "while")
-  gsub(g, n.sons[0])
+  gcond(g, n.sons[0])
   putWithSpace(g, tkColon, ":")
   initContext(c)
   if longMode(g, n) or (lsub(g, n.sons[1]) + g.lineLen > MaxLineLen):
@@ -715,7 +722,7 @@ proc gcase(g: var TSrcGen, n: PNode) =
   var last = if n.sons[length-1].kind == nkElse: -2 else: -1
   if longMode(g, n, 0, last): incl(c.flags, rfLongMode)
   putWithSpace(g, tkCase, "case")
-  gsub(g, n.sons[0])
+  gcond(g, n.sons[0])
   gcoms(g)
   optNL(g)
   gsons(g, n, c, 1, last)
@@ -1102,13 +1109,13 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext) =
     put(g, tkAccent, "`")
   of nkIfExpr:
     putWithSpace(g, tkIf, "if")
-    if n.len > 0: gsub(g, n.sons[0], 0)
+    if n.len > 0: gcond(g, n.sons[0].sons[0])
     putWithSpace(g, tkColon, ":")
     if n.len > 0: gsub(g, n.sons[0], 1)
     gsons(g, n, emptyContext, 1)
   of nkElifExpr:
     putWithSpace(g, tkElif, " elif")
-    gsub(g, n, 0)
+    gcond(g, n[0])
     putWithSpace(g, tkColon, ":")
     gsub(g, n, 1)
   of nkElseExpr:

tests/macros/tmacrostmt.nim

@@ -57,5 +57,21 @@ proc test_block(x, y : int): int =
     result = x
     result = y
 
+#------------------------------------
+# bugs #8348
+
+template `>`(x, y: untyped): untyped =
+  ## "is greater" operator. This is the same as ``y < x``.
+  y < x
+
+proc test_cond_stmtlist(x, y: int): int =
+  result = x
+  if x > y:
+    result = x
+
+
 repr_and_parse(one_if_proc)
 repr_and_parse(test_block)
+repr_and_parse(test_cond_stmtlist)
+
+