From: Johannes Schindelin <johannes.schindelin@xxxxxx> In 4dc42c6c186 (mingw: refuse paths containing reserved names, 2019-12-21), we started disallowing file names that are reserved, e.g. `NUL`, `CONOUT$`, etc. This included `COM<n>` where `<n>` is a digit. Unfortunately, this includes `COM0` but only `COM1`, ..., `COM9` are reserved, according to the official documentation, `COM0` is mentioned in the "NT Namespaces" section but it is explicitly _omitted_ from the list of reserved names: https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#naming-conventions Tests corroborate this: it is totally possible to write a file called `com0.c` on Windows 10, but not `com1.c`. So let's tighten the code to disallow only the reserved `COM<n>` file names, but to allow `COM0` again. This fixes https://github.com/git-for-windows/git/issues/2470. Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx> --- mingw: handle COM0 correctly The code to prevent the reserved COM<n> file names erred on the side of simple code, and sadly sacrificed correctness while at it. This fixes it. Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-754%2Fdscho%2Fcom0-is-not-a-reserved-name-v1 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-754/dscho/com0-is-not-a-reserved-name-v1 Pull-Request: https://github.com/git/git/pull/754 compat/mingw.c | 8 +++++--- t/t0060-path-utils.sh | 2 ++ 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/compat/mingw.c b/compat/mingw.c index d14065d60ec..835a340211e 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -2581,12 +2581,14 @@ int is_valid_win32_path(const char *path, int allow_literal_nul) continue; } break; - case 'c': case 'C': /* COM<N>, CON, CONIN$, CONOUT$ */ + case 'c': case 'C': + /* COM1 ... COM9, CON, CONIN$, CONOUT$ */ if ((c = path[++i]) != 'o' && c != 'O') goto not_a_reserved_name; c = path[++i]; - if (c == 'm' || c == 'M') { /* COM<N> */ - if (!isdigit(path[++i])) + if (c == 'm' || c == 'M') { /* COM1 ... COM9 */ + c = path[++i]; + if (c < '1' || c > '9') goto not_a_reserved_name; } else if (c == 'n' || c == 'N') { /* CON */ c = path[i + 1]; diff --git a/t/t0060-path-utils.sh b/t/t0060-path-utils.sh index 2ea2d00c39a..56db5c8abab 100755 --- a/t/t0060-path-utils.sh +++ b/t/t0060-path-utils.sh @@ -476,6 +476,7 @@ test_expect_success MINGW 'is_valid_path() on Windows' ' C:\\git \ comm \ conout.c \ + com0.c \ lptN \ \ --not \ @@ -488,6 +489,7 @@ test_expect_success MINGW 'is_valid_path() on Windows' ' "AUX.c" \ "abc/conOut\$ .xyz/test" \ lpt8 \ + com9.c \ "lpt*" \ Nul \ "PRN./abc" base-commit: 9fadedd637b312089337d73c3ed8447e9f0aa775 -- gitgitgadget
