Updated things related to the parallels-iso builder to correspond to @azr's suggestions.

builder/parallels/common/hw_config.go

@@ -23,7 +23,6 @@ func (c *HWConfig) Prepare(ctx *interpolate.Context) []error {
 	// Hardware and cpu options
 	if c.CpuCount < 0 {
 		errs = append(errs, fmt.Errorf("An invalid number of cpus was specified (cpus < 0): %d", c.CpuCount))
-		c.CpuCount = 0
 	}
 	if c.CpuCount == 0 {
 		c.CpuCount = 1
@@ -31,7 +30,6 @@ func (c *HWConfig) Prepare(ctx *interpolate.Context) []error {
 
 	if c.MemorySize < 0 {
 		errs = append(errs, fmt.Errorf("An invalid memory size was specified (memory < 0): %d", c.MemorySize))
-		c.MemorySize = 0
 	}
 	if c.MemorySize == 0 {
 		c.MemorySize = 512
@@ -46,5 +44,5 @@ func (c *HWConfig) Prepare(ctx *interpolate.Context) []error {
 		c.USB = false
 	}
 
-	return nil
+	return errs
 }

website/source/docs/builders/parallels-iso.html.md.erb

@@ -103,7 +103,7 @@ builder.
     specified, the default is 10 seconds.
 
 -   `cpus` (number) - The number of cpus to use for building the VM.
-    Defaults to building with just one.
+    Defaults to `1`.
 
 -   `disk_size` (number) - The size, in megabytes, of the hard disk to create
     for the VM. By default, this is 40000 (about 40 GB).