Merge branch 'devel' of github.com:nim-lang/Nim into devel

lib/pure/collections/queues.nim

@@ -152,11 +152,13 @@ proc add*[T](q: var Queue[T], item: T) =
   q.data[q.wr] = item
   q.wr = (q.wr + 1) and q.mask
 
+proc default[T](t: typedesc[T]): T {.inline.} = discard
 proc pop*[T](q: var Queue[T]): T {.inline, discardable.} =
   ## Remove and returns the first (oldest) element of the queue `q`.
   emptyCheck(q)
   dec q.count
   result = q.data[q.rd]
+  q.data[q.rd] = default(type(result))
   q.rd = (q.rd + 1) and q.mask
 
 proc enqueue*[T](q: var Queue[T], item: T) =

lib/pure/collections/tables.nim

@@ -16,6 +16,39 @@
 ## semantics, this means that ``=`` performs a copy of the hash table.
 ## For **reference** semantics use the ``Ref`` variant: ``TableRef``,
 ## ``OrderedTableRef``, ``CountTableRef``.
+## To give an example, when `a` is a Table, then `var b = a` gives `b`
+## as a new independent table. b is initialised with the contents of `a`.
+## Changing `b` does not affect `a` and vice versa:
+##
+## .. code-block::
+##   import tables
+##
+##   var
+##     a = {1: "one", 2: "two"}.toTable  # creates a Table
+##     b = a
+##
+##   echo a, b  # output: {1: one, 2: two}{1: one, 2: two}
+##
+##   b[3] = "three"
+##   echo a, b  # output: {1: one, 2: two}{1: one, 2: two, 3: three}
+##   echo a == b  # output: false
+##
+## On the other hand, when `a` is a TableRef instead, then changes to `b` also affect `a`.
+## Both `a` and `b` reference the same data structure:
+##
+## .. code-block::
+##   import tables
+##
+##   var
+##     a = {1: "one", 2: "two"}.newTable  # creates a TableRef
+##     b = a
+##
+##   echo a, b  # output: {1: one, 2: two}{1: one, 2: two}
+##
+##   b[3] = "three"
+##   echo a, b  # output: {1: one, 2: two, 3: three}{1: one, 2: two, 3: three}
+##   echo a == b  # output: true
+##
 ##
 ## If you are using simple standard types like ``int`` or ``string`` for the
 ## keys of the table you won't have any problems, but as soon as you try to use

lib/pure/json.nim

@@ -1127,7 +1127,7 @@ proc parseJson(p: var JsonParser): JsonNode =
     discard getTok(p)
     while p.tok != tkCurlyRi:
       if p.tok != tkString:
-        raiseParseErr(p, "string literal as key expected")
+        raiseParseErr(p, "string literal as key")
       var key = p.a
       discard getTok(p)
       eat(p, tkColon)

lib/system/gc.nim

@@ -452,10 +452,13 @@ proc rawNewObj(typ: PNimType, size: int, gch: var GcHeap): pointer =
   gcAssert((cast[ByteAddress](res) and (MemAlign-1)) == 0, "newObj: 2")
   # now it is buffered in the ZCT
   res.typ = typ
-  when leakDetector and not hasThreadSupport:
-    if framePtr != nil and framePtr.prev != nil:
-      res.filename = framePtr.prev.filename
-      res.line = framePtr.prev.line
+  when leakDetector:
+    res.filename = nil
+    res.line = 0
+    when not hasThreadSupport:
+      if framePtr != nil and framePtr.prev != nil:
+        res.filename = framePtr.prev.filename
+        res.line = framePtr.prev.line
   # refcount is zero, color is black, but mark it to be in the ZCT
   res.refcount = ZctFlag
   sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3")
@@ -503,10 +506,13 @@ proc newObjRC1(typ: PNimType, size: int): pointer {.compilerRtl.} =
   sysAssert((cast[ByteAddress](res) and (MemAlign-1)) == 0, "newObj: 2")
   # now it is buffered in the ZCT
   res.typ = typ
-  when leakDetector and not hasThreadSupport:
-    if framePtr != nil and framePtr.prev != nil:
-      res.filename = framePtr.prev.filename
-      res.line = framePtr.prev.line
+  when leakDetector:
+    res.filename = nil
+    res.line = 0
+    when not hasThreadSupport:
+      if framePtr != nil and framePtr.prev != nil:
+        res.filename = framePtr.prev.filename
+        res.line = framePtr.prev.line
   res.refcount = rcIncrement # refcount is 1
   sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3")
   when logGC: writeCell("new cell", res)

lib/system/nimscript.nim

@@ -65,6 +65,21 @@ proc hint*(name: string; val: bool) =
   let v = if val: "on" else: "off"
   hintImpl(name & "]:" & v, "hint[" & name & "]:" & v)
 
+proc patchFile*(package, filename, replacement: string) =
+  ## Overrides the location of a given file belonging to the
+  ## passed package.
+  ## If the ``replacement`` is not an absolute path, the path
+  ## is interpreted to be local to the Nimscript file that contains
+  ## the call to ``patchFile``, Nim's ``--path`` is not used at all
+  ## to resolve the filename!
+  ##
+  ## Example:
+  ##
+  ## .. code-block:: nim
+  ##
+  ##   patchFile("stdlib", "asyncdispatch", "patches/replacement")
+  discard
+
 proc getCommand*(): string =
   ## Gets the Nim command that the compiler has been invoked with, for example
   ## "c", "js", "build", "help".