[PATCH v2 3/4] mingw: make failures to unlink or move raise a question
- From
Heiko Voigt <hvoigt@hvoigt.net>
- Date
- Nov 7, 2010, 14:56 UTC
- Message-ID
- <b25a0668848fd85521da9b7dd7e1ca82c2c16e7f.1289139299.git.hvoigt@hvoigt.net>
- In-Reply-To
- <cover.1289139299.git.hvoigt@hvoigt.net>
On Windows in case a program is accessing a file unlink or move operations may fail. To give the user a chance to correct this we simply wait until the user asks us to retry or fail.
This is useful because of the following use case which seem to happen rarely but when it does it is a mess:
After making some changes the user realizes that he was on the incorrect branch. When trying to change the branch some file is still in use by some other process and git stops in the middle of changing branches. Now the user has lots of files with changes mixed with his own. This is especially confusing on repositories that contain lots of files.
Although the recent implementation of automatic retry makes this scenario much more unlikely lets provide a fallback as a last resort.
Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net> --- compat/mingw.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 82 insertions(+), 0 deletions(-)
diff --git a/compat/mingw.c b/compat/mingw.c index bf9ffb8..b66bf89 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -3,6 +3,7 @@ #include <conio.h> #include "../strbuf.h" #include "../cache.h" +#include "../run-command.h" unsigned int _CRT_fmode = _O_BINARY; static const int delay[] = { 0, 1, 10, 20, 40 }; @@ -163,6 +164,78 @@ int mingw_mkdir(const char *path, int mode) return ret; } +static int read_yes_no_answer() +{ + char answer[1024]; + + if (fgets(answer, sizeof(answer), stdin)) { + size_t answer_len = strlen(answer); + int got_full_line = 0, c; + + /* remove the newline */ + if (answer_len >= 2 && answer[answer_len-2] == '\r') { + answer[answer_len-2] = '\0'; + got_full_line = 1; + } + else if (answer_len >= 1 && answer[answer_len-1] == '\n') { + answer[answer_len-1] = '\0'; + got_full_line = 1; + } + /* flush the buffer in case we did not get the full line */ + if (!got_full_line) + while((c = getchar()) != EOF && c != '\n'); + } else + /* we could not read, return the + * default answer which is no */ + return 0; + + if (answer[0] == 'y' && strlen(answer) == 1) + return 1; + if (!strncasecmp(answer, "yes", sizeof(answer))) + return 1; + if (answer[0] == 'n' && strlen(answer) == 1) + return 0; + if (!strncasecmp(answer, "no", sizeof(answer))) + return 0; + + /* did not find an answer we understand */ + return -1; +} + +static int ask_user_yes_no(const char *format, ...) +{ + char question[4096]; + const char *retry_hook[] = { NULL, NULL, NULL }; + va_list args; + + if ((retry_hook[0] = getenv("GIT_ASK_YESNO"))) { + + va_start(args, format); + vsnprintf(question, sizeof(question), format, args); + va_end(args); + + retry_hook[1] = question; + return !run_command_v_opt(retry_hook, 0); + } + + if (!isatty(_fileno(stdin))) + return 0; + + while (1) { + int answer; + va_start(args, format); + vfprintf(stderr, format, args); + va_end(args); + fprintf(stderr, " (y/n)? "); + + if ((answer = read_yes_no_answer()) >= 0) + return answer; + + fprintf(stderr, "Sorry, I did not understand your answer. " + "Please type 'y' or 'n'\n"); + } +} + #undef unlink int mingw_unlink(const char *pathname) { @@ -183,6 +256,10 @@ int mingw_unlink(const char *pathname) Sleep(delay[tries]); tries++; } + while (ret == -1 && is_file_in_use_error() && + ask_user_yes_no("Unlink of file '%s' failed. " + "Should I try again?", pathname)) + ret = unlink(pathname); return ret; } @@ -1343,6 +1420,11 @@ repeat: tries++; goto repeat; } + if (gle == ERROR_ACCESS_DENIED && + ask_user_yes_no("Rename from '%s' to '%s' failed. " + "Should I try again?", pold, pnew)) + goto repeat; + errno = EACCES; return -1; }
-- 1.7.2.2.177.geec0d