Fix dir_item::reduce()

- use while-loop to remove initial './'
- always use spos and reset to pre-len when re-assembling pre+post
- break resolve loop once on found idx == npos
- limit loop to spos <= haystack.size()-pattern_size

- resolve '/./':
  - remove dead-case '_dot == pre' as resolved upfront

- resolve '/../':
  - test non-starting '/..' at end of pre -> no change. E.g. '../../../bbb'
  - case 'pre_str = direname(pre)': test '.' (first dir removed)

3 files changed, 133 insertions, 48 deletions

diff --git a/src/file_util.cpp b/src/file_util.cpp
index 5634683..d8ebccd 100644
--- a/src/file_util.cpp
+++ b/src/file_util.cpp
@@ -138,7 +138,7 @@ std::unique_ptr<dir_item::backed_string_view> dir_item::reduce(const std::string
     }
 
     // remove initial './'
-    if( 0 == path2->view.find(_dot_slash) ) {
+    while( 0 == path2->view.find(_dot_slash) ) {
         path2->view = path2->view.substr(2, path2->view.size()-2);
     }
 
@@ -163,64 +163,78 @@ std::unique_ptr<dir_item::backed_string_view> dir_item::reduce(const std::string
     }
 
     // resolve '/./'
+    size_t spos=0;
     size_t idx;
     do {
-        idx = path2->view.find(_slash_dot_slash);
-        if( std::string_view::npos != idx ) {
-            std::string_view pre = path2->view.substr(0, idx);
-            if( 0 == pre.size() ) {
-                // case '/./bbb' -> '/bbb'
-                path2->view = path2->view.substr(idx+2);
-            } else if( _dot == pre ) {
-                // case '././bbb' -> 'bbb'
-                path2->view = path2->view.substr(idx+3);
-            } else {
-                // case '/zzz/aaa/./bbb' -> '/zzz/aaa/bbb'
-                const std::string post( path2->view.substr(idx+2) );
-                path2->backup_and_append( pre, post );
-            }
-            if constexpr ( _debug ) {
-                jau::fprintf_td(stderr, "X.2.2: path2: '%s'\n", path2->to_string(true).c_str());
-            }
+        idx = path2->view.find(_slash_dot_slash, spos);
+        if constexpr ( _debug ) {
+            jau::fprintf_td(stderr, "X.2.1: path2: spos %zu, idx %zu, '%s'\n", spos, idx, path2->to_string(true).c_str());
+        }
+        if( std::string_view::npos == idx ) {
+            break;
+        }
+        std::string_view pre = path2->view.substr(0, idx);
+        if( 0 == pre.size() ) {
+            // case '/./bbb' -> '/bbb'
+            path2->view = path2->view.substr(idx+2);
+            spos = 0;
+        } else {
+            // case '/zzz/aaa/./bbb' -> '/zzz/aaa/bbb'
+            const std::string post( path2->view.substr(idx+2) );
+            path2->backup_and_append( pre, post );
+            spos = pre.size();
+        }
+        if constexpr ( _debug ) {
+            jau::fprintf_td(stderr, "X.2.2: path2: spos %zu, '%s'\n", spos, path2->to_string(true).c_str());
         }
-    } while( idx != std::string_view::npos );
+    } while( spos <= path2->view.size()-3 );
     if constexpr ( _debug ) {
         jau::fprintf_td(stderr, "X.2.X: path2: '%s'\n", path2->to_string(true).c_str());
     }
 
     // resolve '/../'
-    size_t spos=0;
+    spos=0;
     do {
         idx = path2->view.find(_slash_dotdot_slash, spos);
-        if( std::string_view::npos != idx ) {
-            if( 0 == idx ) {
-                // case '/../bbb' -> Error, End
-                WARN_PRINT("dir_item::resolve: '..' resolution error: '%s' -> '%s'", std::string(path_).c_str(), path2->to_string().c_str());
-                return path2;
-            }
-            std::string_view pre = path2->view.substr(0, idx);
-            if( _dotdot == pre ) {
-                // case '../../bbb' -> '../../bbb' unchanged
-                spos = idx+4;
-            } else if( _dot == pre ) {
-                // case './../bbb' -> '../bbb'
-                path2->view = path2->view.substr(idx+1);
+        if constexpr ( _debug ) {
+            jau::fprintf_td(stderr, "X.3.1: path2: spos %zu, idx %zu, '%s'\n", spos, idx, path2->to_string(true).c_str());
+        }
+        if( std::string_view::npos == idx ) {
+            break;
+        }
+        if( 0 == idx ) {
+            // case '/../bbb' -> Error, End
+            WARN_PRINT("dir_item::resolve: '..' resolution error: '%s' -> '%s'", std::string(path_).c_str(), path2->to_string().c_str());
+            return path2;
+        }
+        std::string_view pre = path2->view.substr(0, idx);
+        if( 2 == idx && _dotdot == pre ) {
+            // case '../../bbb' -> '../../bbb' unchanged
+            spos = idx+4;
+        } else if( 3 <= idx && _slash_dotdot == path2->view.substr(idx-3, 3) ) {
+            // case '../../../bbb' -> '../../../bbb' unchanged
+            spos = idx+4;
+        } else {
+            std::string pre_str = jau::fs::dirname( pre );
+            if( _slash == pre_str ) {
+                // case '/aaa/../bbb' -> '/bbb'
+                path2->view = path2->view.substr(idx+3);
+                spos = 0;
+            } else if( _dot == pre_str ) {
+                // case 'aaa/../bbb' -> 'bbb'
+                path2->view = path2->view.substr(idx+4);
+                spos = 0;
             } else {
-                std::string pre_str = jau::fs::dirname( pre );
-                if( _slash == pre_str ) {
-                    // case '/aaa/../bbb' -> '/bbb'
-                    path2->view = path2->view.substr(idx+3);
-                } else {
-                    // case '/zzz/aaa/../bbb' -> '/zzz/bbb'
-                    const std::string post( path2->view.substr(idx+3) );
-                    path2->backup_and_append( pre_str, post );
-                }
-            }
-            if constexpr ( _debug ) {
-                jau::fprintf_td(stderr, "X.3.2: path2: '%s'\n", path2->to_string(true).c_str());
+                // case '/zzz/aaa/../bbb' -> '/zzz/bbb'
+                const std::string post( path2->view.substr(idx+3) );
+                path2->backup_and_append( pre_str, post );
+                spos = pre_str.size();
             }
         }
-    } while( idx != std::string_view::npos );
+        if constexpr ( _debug ) {
+            jau::fprintf_td(stderr, "X.3.2: path2: spos %zu, '%s'\n", spos, path2->to_string(true).c_str());
+        }
+    } while( spos <= path2->view.size()-4 );
     if constexpr ( _debug ) {
         jau::fprintf_td(stderr, "X.3.X: path2: '%s'\n", path2->to_string(true).c_str());
     }
diff --git a/test/java/jau/test/fs/TestFileUtils01.java b/test/java/jau/test/fs/TestFileUtils01.java
index 78cfecf..55e0f7f 100644
--- a/test/java/jau/test/fs/TestFileUtils01.java
+++ b/test/java/jau/test/fs/TestFileUtils01.java
@@ -420,7 +420,43 @@ public class TestFileUtils01 extends FileUtilBaseTest {
             PrintUtil.println(System.err, "test04_dir_item: 60 '"+path1_+" -> "+di.toString()+" -> '"+di.path()+"'\n");
             Assert.assertTrue( "../../test_data".equals( di.dirname() ) );
             Assert.assertTrue( "file_01_slink09R1.txt".equals( di.basename() ) );
-            Assert.assertTrue( "../../test_data/file_01_slink09R1.txt".equals( di.path() ) );
+            Assert.assertTrue( path1_.equals( di.path() ) );
+        }
+
+        {
+            final String path1_ = "../../../jaulib/test_data";
+            final DirItem di = new DirItem(path1_);
+            PrintUtil.println(System.err, "test04_dir_item: 61 '"+path1_+" -> "+di.toString()+" -> '"+di.path()+"'\n");
+            Assert.assertTrue( "../../../jaulib".equals( di.dirname() ) );
+            Assert.assertTrue( "test_data".equals( di.basename() ) );
+            Assert.assertTrue( path1_.equals( di.path() ) );
+        }
+
+        {
+            final String path1_ = "../../../../jaulib/test_data";
+            final DirItem di = new DirItem(path1_);
+            PrintUtil.println(System.err, "test04_dir_item: 62 '"+path1_+" -> "+di.toString()+" -> '"+di.path()+"'\n");
+            Assert.assertTrue( "../../../../jaulib".equals( di.dirname() ) );
+            Assert.assertTrue( "test_data".equals( di.basename() ) );
+            Assert.assertTrue( path1_.equals( di.path() ) );
+        }
+
+        {
+            final String path1_ = "././././jaulib/test_data";
+            final DirItem di = new DirItem(path1_);
+            PrintUtil.println(System.err, "test04_dir_item: 63 '"+path1_+" -> "+di.toString()+" -> '"+di.path()+"'\n");
+            Assert.assertTrue( "jaulib".equals( di.dirname() ) );
+            Assert.assertTrue( "test_data".equals( di.basename() ) );
+            Assert.assertTrue( "jaulib/test_data".equals( di.path() ) );
+        }
+
+        {
+            final String path1_ = "a/././././jaulib/test_data";
+            final DirItem di = new DirItem(path1_);
+            PrintUtil.println(System.err, "test04_dir_item: 64 '"+path1_+" -> "+di.toString()+" -> '"+di.path()+"'\n");
+            Assert.assertTrue( "a/jaulib".equals( di.dirname() ) );
+            Assert.assertTrue( "test_data".equals( di.basename() ) );
+            Assert.assertTrue( "a/jaulib/test_data".equals( di.path() ) );
         }
 
         {
diff --git a/test/test_fileutils01.cpp b/test/test_fileutils01.cpp
index d10be65..54a59e8 100644
--- a/test/test_fileutils01.cpp
+++ b/test/test_fileutils01.cpp
@@ -396,7 +396,42 @@ class TestFileUtil01 : TestFileUtilBase {
             INFO_STR("\n\ntest04_dir_item: 60 '"+path1_+" -> "+di.to_string()+" -> '"+di.path()+"'\n");
             REQUIRE( "../../test_data" == di.dirname() );
             REQUIRE( "file_01_slink09R1.txt" == di.basename() );
-            REQUIRE( "../../test_data/file_01_slink09R1.txt" == di.path() );
+            REQUIRE( path1_ == di.path() );
+        }
+
+        {
+            const std::string path1_ = "../../../jaulib/test_data";
+            const jau::fs::dir_item di(path1_);
+            INFO_STR("\n\ntest04_dir_item: 61 '"+path1_+" -> "+di.to_string()+" -> '"+di.path()+"'\n");
+            REQUIRE( "../../../jaulib" == di.dirname() );
+            REQUIRE( "test_data" == di.basename() );
+            REQUIRE( path1_ == di.path() );
+        }
+
+        {
+            const std::string path1_ = "../../../../jaulib/test_data";
+            const jau::fs::dir_item di(path1_);
+            INFO_STR("\n\ntest04_dir_item: 62 '"+path1_+" -> "+di.to_string()+" -> '"+di.path()+"'\n");
+            REQUIRE( "../../../../jaulib" == di.dirname() );
+            REQUIRE( "test_data" == di.basename() );
+            REQUIRE( path1_ == di.path() );
+        }
+
+        {
+            const std::string path1_ = "././././jaulib/test_data";
+            const jau::fs::dir_item di(path1_);
+            INFO_STR("\n\ntest04_dir_item: 63 '"+path1_+" -> "+di.to_string()+" -> '"+di.path()+"'\n");
+            REQUIRE( "jaulib" == di.dirname() );
+            REQUIRE( "test_data" == di.basename() );
+            REQUIRE( "jaulib/test_data" == di.path() );
+        }
+        {
+            const std::string path1_ = "a/././././jaulib/test_data";
+            const jau::fs::dir_item di(path1_);
+            INFO_STR("\n\ntest04_dir_item: 64 '"+path1_+" -> "+di.to_string()+" -> '"+di.path()+"'\n");
+            REQUIRE( "a/jaulib" == di.dirname() );
+            REQUIRE( "test_data" == di.basename() );
+            REQUIRE( "a/jaulib/test_data" == di.path() );
         }
 
         {