OpenFileGDB: be robust to unusual .gdbindexes files with weird/corrupted/not-understood entries

autotest/ogr/data/filegdb/corrupted_gdbindexes.gdb/timestamps

@@ -0,0 +1 @@
+ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ

autotest/ogr/ogr_openfilegdb.py

@@ -2942,3 +2942,19 @@ def test_ogr_openfilegdb_arc_interior_point_bug_line():
             f,
             "MULTILINESTRING ((37252520.1717 7431529.9154,38549084.9654 758964.7573))",
         )
+
+
+###############################################################################
+# Test https://github.com/OSGeo/gdal/issues/11295 where .gdbindexes contains
+# entry with unusual (corrupted ? disabled?) entries
+
+
+def test_ogr_openfilegdb_weird_gdbindexes():
+
+    # File a00000009.gdbindexes has been replaced by file a00000029.gdbindexes
+    # from attachment of https://github.com/OSGeo/gdal/issues/11295#issuecomment-2491158506
+    with ogr.Open("data/filegdb/corrupted_gdbindexes.gdb") as ds:
+        lyr = ds.GetLayer(0)
+        lyr.SetAttributeFilter("id = '1'")
+        f = lyr.GetNextFeature()
+        assert f

ogr/ogrsf_frmts/openfilegdb/filegdbtable.cpp

@@ -2537,6 +2537,7 @@ int FileGDBTable::GetIndexCount()
         CPLDebug("OpenFileGDB", ".gdbindexes v9 not handled yet");
         return 0;
     }
+
     returnErrorAndCleanupIf(nIndexCount >=
                                 static_cast<size_t>(GetFieldCount() + 1) * 10,
                             VSIFree(pabyIdx));
@@ -2547,7 +2548,7 @@ int FileGDBTable::GetIndexCount()
         returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
                                     sizeof(GUInt32),
                                 VSIFree(pabyIdx));
-        GUInt32 nIdxNameCarCount = GetUInt32(pabyCur, 0);
+        const GUInt32 nIdxNameCarCount = GetUInt32(pabyCur, 0);
         pabyCur += sizeof(GUInt32);
         returnErrorAndCleanupIf(nIdxNameCarCount > 1024, VSIFree(pabyIdx));
         returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
@@ -2557,13 +2558,56 @@ int FileGDBTable::GetIndexCount()
             ReadUTF16String(pabyCur, nIdxNameCarCount));
         pabyCur += 2 * nIdxNameCarCount;
 
+        // 4 "magic fields"
+        returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
+                                    sizeof(GUInt16) + sizeof(GUInt32) +
+                                        sizeof(GUInt16) + sizeof(GUInt32),
+                                VSIFree(pabyIdx));
+        // const GUInt16 nMagic1 = GetUInt16(pabyCur, 0);
+        const GUInt32 nMagic2 = GetUInt32(pabyCur + sizeof(GUInt16), 0);
+        const GUInt16 nMagic3 =
+            GetUInt16(pabyCur + sizeof(GUInt16) + sizeof(GUInt32), 0);
+        if (!((nMagic2 == 2 && nMagic3 == 0) ||
+              (nMagic2 == 4 && nMagic3 == 0) ||
+              (nMagic2 == 16 && nMagic3 == 65535)))
+        {
+            // Cf files a00000029.gdbindexes, a000000ea.gdbindexes, a000000ed.gdbindexes,
+            // a000000f8.gdbindexes, a000000fb.gdbindexes, a00000103.gdbindexes
+            // from https://github.com/OSGeo/gdal/issues/11295#issuecomment-2491158506
+            CPLDebug("OpenFileGDB", "Reading %s", pszIndexesName);
+            CPLDebug(
+                "OpenFileGDB",
+                "Strange (deleted?) index descriptor at index %u of name %s", i,
+                osIndexName.c_str());
+
+            // Skip magic fields
+            pabyCur += sizeof(GUInt16);
+
+            const GUInt32 nColNameCarCount = nMagic2;
+            pabyCur += sizeof(GUInt32);
+            returnErrorAndCleanupIf(nColNameCarCount > 1024, VSIFree(pabyIdx));
+            returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
+                                        2 * nColNameCarCount,
+                                    VSIFree(pabyIdx));
+            pabyCur += 2 * nColNameCarCount;
+
+            // Skip magic field
+            returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
+                                        sizeof(GUInt16),
+                                    VSIFree(pabyIdx));
+            pabyCur += sizeof(GUInt16);
+
+            continue;
+        }
+
         // Skip magic fields
-        pabyCur += 2 + 4 + 2 + 4;
+        pabyCur += sizeof(GUInt16) + sizeof(GUInt32) + sizeof(GUInt16) +
+                   sizeof(GUInt32);
 
         returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
                                     sizeof(GUInt32),
                                 VSIFree(pabyIdx));
-        GUInt32 nColNameCarCount = GetUInt32(pabyCur, 0);
+        const GUInt32 nColNameCarCount = GetUInt32(pabyCur, 0);
         pabyCur += sizeof(GUInt32);
         returnErrorAndCleanupIf(nColNameCarCount > 1024, VSIFree(pabyIdx));
         returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
@@ -2574,7 +2618,10 @@ int FileGDBTable::GetIndexCount()
         pabyCur += 2 * nColNameCarCount;
 
         // Skip magic field
-        pabyCur += 2;
+        returnErrorAndCleanupIf(static_cast<GUInt32>(pabyEnd - pabyCur) <
+                                    sizeof(GUInt16),
+                                VSIFree(pabyIdx));
+        pabyCur += sizeof(GUInt16);
 
         auto poIndex = std::make_unique<FileGDBIndex>();
         poIndex->m_osIndexName = osIndexName;