[php-src] Issue #12574: RecursiveDirectoryIterator misbehaves if the directory gets modified while iterating

Issue: https://github.com/php/php-src/issues/12574 Author: caco3 ### Description I am trying to run a simple PHP script on the FreeBSD 12.4 system of my web hoster (hostpoint.ch). It seems that there is some non-standard behaviour in it. # Preparations setup a src directory with a lot of files: ```bash mkdir src for i in {1..500}; do touch src/$i; done ``` create a php script using following content: ```php <?php function getRecursiveDirectoryIterator(?string $folder = null): \RecursiveIteratorIterator { return new \RecursiveIteratorIterator( new \RecursiveDirectoryIterator($folder, \RecursiveDirectoryIterator::SKIP_DOTS), \RecursiveIteratorIterator::CHILD_FIRST ); } $i = 0; mkdir("dst"); $fileList = iterator_to_array(getRecursiveDirectoryIterator("src"), true); foreach ($fileList as $path => $fileInfo) { $i++; $newPath = str_replace("src", "dst", $path); echo("$i: $path -> $newPath\n"); rename($path, $newPath); // <- makes the iterator to break } echo("EOF"); ?> ``` # Expected output It is expected that all 500 files get moved from src to dst: ``` 1: src/1 -> dst/1 2: src/2 -> dst/2 3: src/3 -> dst/3 4: src/4 -> dst/4 5: src/5 -> dst/5 6: src/6 -> dst/6 [..] 496: src/496 -> dst/496 497: src/497 -> dst/497 498: src/498 -> dst/498 499: src/499 -> dst/499 500: src/500 -> dst/500 ``` # Effective Output The iterator has 2 glitches, files 95..188 and 285..380 get skipped: ``` 1: src/1 -> dst/1 2: src/2 -> dst/2 3: src/3 -> dst/3 4: src/4 -> dst/4 5: src/5 -> dst/5 6: src/6 -> dst/6 7: src/7 -> dst/7 8: src/8 -> dst/8 9: src/9 -> dst/9 10: src/10 -> dst/10 11: src/11 -> dst/11 12: src/12 -> dst/12 13: src/13 -> dst/13 14: src/14 -> dst/14 15: src/15 -> dst/15 16: src/16 -> dst/16 17: src/17 -> dst/17 18: src/18 -> dst/18 19: src/19 -> dst/19 20: src/20 -> dst/20 21: src/21 -> dst/21 22: src/22 -> dst/22 23: src/23 -> dst/23 24: src/24 -> dst/24 25: src/25 -> dst/25 26: src/26 -> dst/26 27: src/27 -> dst/27 28: src/28 -> dst/28 29: src/29 -> dst/29 30: src/30 -> dst/30 31: src/31 -> dst/31 32: src/32 -> dst/32 33: src/33 -> dst/33 34: src/34 -> dst/34 35: src/35 -> dst/35 36: src/36 -> dst/36 37: src/37 -> dst/37 38: src/38 -> dst/38 39: src/39 -> dst/39 40: src/40 -> dst/40 41: src/41 -> dst/41 42: src/42 -> dst/42 43: src/43 -> dst/43 44: src/44 -> dst/44 45: src/45 -> dst/45 46: src/46 -> dst/46 47: src/47 -> dst/47 48: src/48 -> dst/48 49: src/49 -> dst/49 50: src/50 -> dst/50 51: src/51 -> dst/51 52: src/52 -> dst/52 53: src/53 -> dst/53 54: src/54 -> dst/54 55: src/55 -> dst/55 56: src/56 -> dst/56 57: src/57 -> dst/57 58: src/58 -> dst/58 59: src/59 -> dst/59 60: src/60 -> dst/60 61: src/61 -> dst/61 62: src/62 -> dst/62 63: src/63 -> dst/63 64: src/64 -> dst/64 65: src/65 -> dst/65 66: src/66 -> dst/66 67: src/67 -> dst/67 68: src/68 -> dst/68 69: src/69 -> dst/69 70: src/70 -> dst/70 71: src/71 -> dst/71 72: src/72 -> dst/72 73: src/73 -> dst/73 74: src/74 -> dst/74 75: src/75 -> dst/75 76: src/76 -> dst/76 77: src/77 -> dst/77 78: src/78 -> dst/78 79: src/79 -> dst/79 80: src/80 -> dst/80 81: src/81 -> dst/81 82: src/82 -> dst/82 83: src/83 -> dst/83 84: src/84 -> dst/84 85: src/85 -> dst/85 86: src/86 -> dst/86 87: src/87 -> dst/87 88: src/88 -> dst/88 89: src/89 -> dst/89 90: src/90 -> dst/90 91: src/91 -> dst/91 92: src/92 -> dst/92 93: src/93 -> dst/93 94: src/94 -> dst/94 95: src/189 -> dst/189 <--- file 95..188 got skipped 96: src/190 -> dst/190 97: src/191 -> dst/191 98: src/192 -> dst/192 99: src/193 -> dst/193 100: src/194 -> dst/194 101: src/195 -> dst/195 102: src/196 -> dst/196 103: src/197 -> dst/197 104: src/198 -> dst/198 105: src/199 -> dst/199 106: src/200 -> dst/200 107: src/201 -> dst/201 108: src/202 -> dst/202 109: src/203 -> dst/203 110: src/204 -> dst/204 111: src/205 -> dst/205 112: src/206 -> dst/206 113: src/207 -> dst/207 114: src/208 -> dst/208 115: src/209 -> dst/209 116: src/210 -> dst/210 117: src/211 -> dst/211 118: src/212 -> dst/212 119: src/213 -> dst/213 120: src/214 -> dst/214 121: src/215 -> dst/215 122: src/216 -> dst/216 123: src/217 -> dst/217 124: src/218 -> dst/218 125: src/219 -> dst/219 126: src/220 -> dst/220 127: src/221 -> dst/221 128: src/222 -> dst/222 129: src/223 -> dst/223 130: src/224 -> dst/224 131: src/225 -> dst/225 132: src/226 -> dst/226 133: src/227 -> dst/227 134: src/228 -> dst/228 135: src/229 -> dst/229 136: src/230 -> dst/230 137: src/231 -> dst/231 138: src/232 -> dst/232 139: src/233 -> dst/233 140: src/234 -> dst/234 141: src/235 -> dst/235 142: src/236 -> dst/236 143: src/237 -> dst/237 144: src/238 -> dst/238 145: src/239 -> dst/239 146: src/240 -> dst/240 147: src/241 -> dst/241 148: src/242 -> dst/242 149: src/243 -> dst/243 150: src/244 -> dst/244 151: src/245 -> dst/245 152: src/246 -> dst/246 153: src/247 -> dst/247 154: src/248 -> dst/248 155: src/249 -> dst/249 156: src/250 -> dst/250 157: src/251 -> dst/251 158: src/252 -> dst/252 159: src/253 -> dst/253 160: src/254 -> dst/254 161: src/255 -> dst/255 162: src/256 -> dst/256 163: src/257 -> dst/257 164: src/258 -> dst/258 165: src/259 -> dst/259 166: src/260 -> dst/260 167: src/261 -> dst/261 168: src/262 -> dst/262 169: src/263 -> dst/263 170: src/264 -> dst/264 171: src/265 -> dst/265 172: src/266 -> dst/266 173: src/267 -> dst/267 174: src/268 -> dst/268 175: src/269 -> dst/269 176: src/270 -> dst/270 177: src/271 -> dst/271 178: src/272 -> dst/272 179: src/273 -> dst/273 180: src/274 -> dst/274 181: src/275 -> dst/275 182: src/276 -> dst/276 183: src/277 -> dst/277 184: src/278 -> dst/278 185: src/279 -> dst/279 186: src/280 -> dst/280 187: src/281 -> dst/281 188: src/282 -> dst/282 189: src/283 -> dst/283 190: src/284 -> dst/284 191: src/381 -> dst/381 <--- file 285..380 got skipped 192: src/382 -> dst/382 193: src/383 -> dst/383 194: src/384 -> dst/384 195: src/385 -> dst/385 196: src/386 -> dst/386 197: src/387 -> dst/387 198: src/388 -> dst/388 199: src/389 -> dst/389 200: src/390 -> dst/390 201: src/391 -> dst/391 202: src/392 -> dst/392 203: src/393 -> dst/393 204: src/394 -> dst/394 205: src/395 -> dst/395 206: src/396 -> dst/396 207: src/397 -> dst/397 208: src/398 -> dst/398 209: src/399 -> dst/399 210: src/400 -> dst/400 211: src/401 -> dst/401 212: src/402 -> dst/402 213: src/403 -> dst/403 214: src/404 -> dst/404 215: src/405 -> dst/405 216: src/406 -> dst/406 217: src/407 -> dst/407 218: src/408 -> dst/408 219: src/409 -> dst/409 220: src/410 -> dst/410 221: src/411 -> dst/411 222: src/412 -> dst/412 223: src/413 -> dst/413 224: src/414 -> dst/414 225: src/415 -> dst/415 226: src/416 -> dst/416 227: src/417 -> dst/417 228: src/418 -> dst/418 229: src/419 -> dst/419 230: src/420 -> dst/420 231: src/421 -> dst/421 232: src/422 -> dst/422 233: src/423 -> dst/423 234: src/424 -> dst/424 235: src/425 -> dst/425 236: src/426 -> dst/426 237: src/427 -> dst/427 238: src/428 -> dst/428 239: src/429 -> dst/429 240: src/430 -> dst/430 241: src/431 -> dst/431 242: src/432 -> dst/432 243: src/433 -> dst/433 244: src/434 -> dst/434 245: src/435 -> dst/435 246: src/436 -> dst/436 247: src/437 -> dst/437 248: src/438 -> dst/438 249: src/439 -> dst/439 250: src/440 -> dst/440 251: src/441 -> dst/441 252: src/442 -> dst/442 253: src/443 -> dst/443 254: src/444 -> dst/444 255: src/445 -> dst/445 256: src/446 -> dst/446 257: src/447 -> dst/447 258: src/448 -> dst/448 259: src/449 -> dst/449 260: src/450 -> dst/450 261: src/451 -> dst/451 262: src/452 -> dst/452 263: src/453 -> dst/453 264: src/454 -> dst/454 265: src/455 -> dst/455 266: src/456 -> dst/456 267: src/457 -> dst/457 268: src/458 -> dst/458 269: src/459 -> dst/459 270: src/460 -> dst/460 271: src/461 -> dst/461 272: src/462 -> dst/462 273: src/463 -> dst/463 274: src/464 -> dst/464 275: src/465 -> dst/465 276: src/466 -> dst/466 277: src/467 -> dst/467 278: src/468 -> dst/468 279: src/469 -> dst/469 280: src/470 -> dst/470 281: src/471 -> dst/471 282: src/472 -> dst/472 283: src/473 -> dst/473 284: src/474 -> dst/474 285: src/475 -> dst/475 286: src/476 -> dst/476 ``` Note that changing the iterator to create a list and looping through the list works around this issue: ```diff - foreach (getRecursiveDirectoryIterator("src") as $path) { + $fileList = iterator_to_array(getRecursiveDirectoryIterator("src"), true); + foreach ($fileList as $path => $fileInfo) { ``` ### PHP Version 7.4, 8.0, 8.1 ### Operating System FreeBSD 12.4