bug symfony#16742 [Console][ProgressBar] redrawFrequency should never be 0 (dritter)

This PR was submitted for the 2.8 branch but it was merged into the 2.7 branch instead (closes symfony#16742).

Discussion
----------

[Console][ProgressBar] redrawFrequency should never be 0

Set the redraw frequency at least to 1. Setting it to 0 would otherwise produce a "division by zero" error.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

### why?
I had a piece of code that used a ProgressBar and set the redraw frequency to a calculated value. In some cases this calculated value was 0 (or just smaller than 1, internally a cast to `int` is made). In the `setProgress` the redraw frequency is used for a calculation of the period. There the error happens (and shows that redraw frequency should never be 0).

### Ticket
There is no ticket concerning this issue. I could do one, if you want.

### Tests
This gets tested implicitly in `ProgressBarTest::testNonDecoratedOutputWithoutMax`.

Commits
-------

a1c207c Set the redraw frequency at least to 1. Setting it to 0 would otherwise produce an error.

Author: stof

src/Symfony/Component/Console/Helper/ProgressBar.php

@@ -67,10 +67,8 @@ public function __construct(OutputInterface $output, $max = 0)
             // disable overwrite when output does not support ANSI codes.
             $this->overwrite = false;
 
-            if ($this->max > 10) {
-                // set a reasonable redraw frequency so output isn't flooded
-                $this->setRedrawFrequency($max / 10);
-            }
+            // set a reasonable redraw frequency so output isn't flooded
+            $this->setRedrawFrequency($max / 10);
         }
 
         $this->startTime = time();
@@ -316,11 +314,11 @@ public function setFormat($format)
     /**
      * Sets the redraw frequency.
      *
-     * @param int $freq The frequency in steps
+     * @param int|float $freq The frequency in steps
      */
     public function setRedrawFrequency($freq)
     {
-        $this->redrawFreq = (int) $freq;
+        $this->redrawFreq = max((int) $freq, 1);
     }
 
     /**

src/Symfony/Component/Console/Tests/Helper/ProgressBarTest.php

@@ -296,7 +296,7 @@ public function testRegressProgress()
 
     public function testRedrawFrequency()
     {
-        $bar = $this->getMock('Symfony\Component\Console\Helper\ProgressBar', array('display'), array($output = $this->getOutputStream(), 6));
+        $bar = $this->getMock('Symfony\Component\Console\Helper\ProgressBar', array('display'), array($this->getOutputStream(), 6));
         $bar->expects($this->exactly(4))->method('display');
 
         $bar->setRedrawFrequency(2);
@@ -307,6 +307,26 @@ public function testRedrawFrequency()
         $bar->advance(1);
     }
 
+    public function testRedrawFrequencyIsAtLeastOneIfZeroGiven()
+    {
+        $bar = $this->getMock('Symfony\Component\Console\Helper\ProgressBar', array('display'), array($this->getOutputStream()));
+
+        $bar->expects($this->exactly(2))->method('display');
+        $bar->setRedrawFrequency(0);
+        $bar->start();
+        $bar->advance();
+    }
+
+    public function testRedrawFrequencyIsAtLeastOneIfSmallerOneGiven()
+    {
+        $bar = $this->getMock('Symfony\Component\Console\Helper\ProgressBar', array('display'), array($this->getOutputStream()));
+
+        $bar->expects($this->exactly(2))->method('display');
+        $bar->setRedrawFrequency(0.9);
+        $bar->start();
+        $bar->advance();
+    }
+
     /**
      * @requires extension mbstring
      */