Fix edge case when diff changes were exactly "++ " or "-- "

In those cases, sometimes, that was leading to the lines
to be recognised as a new file incorrectly, causing various
troubles later in the process.

Now we look for the two lines in a row, and only when they
have something looking like a path:

- /dev/null
- /path/to/something

Covered with test containing the edge cases.

diff_extract_changes/diff_extract_changes.php

@@ -93,7 +93,7 @@
 class diff_changes_extractor {
 
     /** version of the extractor */
-    const VERSION = '20120120';
+    const VERSION = '20240323';
 
     /** @var string The unified diff file to process */
     protected $file;
@@ -130,9 +130,11 @@ public function process() {
         $inchunk = false; // To determine if we are in a chunk or no
         $deletefile = false; // To detect delete operation and skip those files
         $binaryfile = false; // To detect binary files and handle them specially
+        $afterminus = false; // To detect if we are after a minus (-) line
+        $isnewfile = false; // To detect if we are in a new file
 
         // Skip always these lines
-        $skiplines = array('diff', 'inde', '--- ');
+        $skiplines = array('diff', 'inde');
 
         // Let's read the diff file, line by line.
         $fh = fopen($this->file, 'r');
@@ -155,16 +157,39 @@ public function process() {
                     continue;
                 }
 
+                // If it's the start of a new file (--- ), we mark it for next line.
+                if ($lineheader === '--- ') {
+                    // Only if the line has something looking like a path.
+                    if (preg_match('~^--- a?(/)(.+)$~', $line, $match)) {
+                        if (!empty($match[2]) && !empty($match[1]) && $match[1] === '/') {
+                            $afterminus = true;
+                        }
+                    }
+                }
+
+                // If it's the start of a new file (+++ ), and we are after a minus (--- )
+                // we raise the new file flag.
+                if ($lineheader === '+++ ' && $afterminus) {
+                    // Only if the line has something looking like a path.
+                    if (preg_match('~^\+\+\+ b?(/)(.+)$~', $line, $match)) {
+                        if (!empty($match[2]) && !empty($match[1]) && $match[1] === '/') {
+                            $isnewfile = true;
+                        }
+                    }
+                }
+
                 // If it's one Binary file, we mark it
                 if ($lineheader === 'Bina') {
                     $binaryfile = true;
                 }
 
                 // Detect if we are changing of file
-                if ($lineheader === '+++ ' || $binaryfile) {
+                if ($isnewfile || $binaryfile) {
 
                     $clineinfile = 0;
                     $inchunk = false;
+                    $afterminus = false;
+                    $isnewfile = false;
 
                     // Output interval end
                     if (!empty($clineint)) {
@@ -300,7 +325,7 @@ private function output_begin() {
      */
     private function output_end() {
         if ($this->output == 'xml') {
-            echo '</diffchanges>';
+            echo '</diffchanges>' . PHP_EOL;
         }
     }
 

tests/1-diff_extract_changes.bats

@@ -6,8 +6,8 @@ load libs/shared_setup
 # usage: pssert_diff_extract_changes format fixturefilename expectedfilename
 assert_diff_extract_changes() {
     format=$1
-    fixture=$BATS_TEST_DIRNAME/fixtures/$2
-    expected=$BATS_TEST_DIRNAME/fixtures/$3
+    fixture=$BATS_TEST_DIRNAME/fixtures/diff_extract_changes/$2
+    expected=$BATS_TEST_DIRNAME/fixtures/diff_extract_changes/$3
 
     out=$BATS_TMPDIR/diff_extract_changes-out
 
@@ -17,10 +17,18 @@ assert_diff_extract_changes() {
     rm $out
 }
 
-@test "diff_extract_changes: xml" {
-    assert_diff_extract_changes xml diff_extract_changes-input.patch diff_extract_changes-expected.xml
+@test "diff_extract_changes (normal): xml" {
+    assert_diff_extract_changes xml diff_extract_changes-normal-input.patch diff_extract_changes-normal-expected.xml
 }
 
-@test "diff_extract_changes: txt" {
-    assert_diff_extract_changes txt diff_extract_changes-input.patch diff_extract_changes-expected.txt
+@test "diff_extract_changes (normal): txt" {
+    assert_diff_extract_changes txt diff_extract_changes-normal-input.patch diff_extract_changes-normal-expected.txt
+}
+
+@test "diff_extract_changes (edge): xml" {
+    assert_diff_extract_changes xml diff_extract_changes-edge-input.patch diff_extract_changes-edge-expected.xml
+}
+
+@test "diff_extract_changes (edge): txt" {
+    assert_diff_extract_changes txt diff_extract_changes-edge-input.patch diff_extract_changes-edge-expected.txt
 }

tests/fixtures/diff_extract_changes/diff_extract_changes-edge-expected.txt

@@ -0,0 +1,2 @@
+another_binary.png:
+diff_extract_changes_edge_cases.txt:10-10;13-13;

tests/fixtures/diff_extract_changes/diff_extract_changes-edge-expected.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<diffchanges version="20240323">
+  <file name="another_binary.png">
+  </file>
+  <file name="diff_extract_changes_edge_cases.txt">
+    <lines from="10" to="10"/>
+    <lines from="13" to="13"/>
+  </file>
+</diffchanges>

tests/fixtures/diff_extract_changes/diff_extract_changes-edge-input.patch

@@ -0,0 +1,25 @@
+diff --git a/another_binary.png b/another_binary.png
+new file mode 100644
+index 00000000000..3cb4b3d9aaf
+Binary files /dev/null and b/another_binary.png differ
+diff --git a/diff_extract_changes_edge_cases.txt b/diff_extract_changes_edge_cases.txt
+index 4e020b9abcd..21a2225922f 100644
+--- a/diff_extract_changes_edge_cases.txt
++++ b/diff_extract_changes_edge_cases.txt
+@@ -5,10 +5,9 @@ Let's see how out diff extractor behaves with some edge cases.
+ + 
+ - 
+ ++ 
+--- 
+ +++ 
+---- 
+ ++ 
+--- 
++++ 
+ + 
+ - 
++-- 
+diff --git a/some_binary1.png b/some_binary1.png
+deleted file mode 100644
+index f6277460437..00000000000
+Binary files a/some_binary1.png and /dev/null differ

tests/fixtures/diff_extract_changes-expected.xml → tests/fixtures/diff_extract_changes/diff_extract_changes-normal-expected.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<diffchanges version="20120120">
+<diffchanges version="20240323">
   <file name=".stylelintrc">
     <lines from="1" to="93"/>
   </file>
@@ -506,4 +506,4 @@
     <lines from="67" to="67"/>
     <lines from="241" to="242"/>
   </file>
-</diffchanges>
+</diffchanges>