From f1efb97075d301c05f5fe974b9234f2920e83c27 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Mon, 4 Dec 2017 13:18:25 +0100 Subject: [PATCH] Fix #1635. --- src/nix/search.cc | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/src/nix/search.cc b/src/nix/search.cc index a9dc2d6b9..87cdb2d7e 100644 --- a/src/nix/search.cc +++ b/src/nix/search.cc @@ -214,13 +214,28 @@ struct CmdSearch : SourceExprCommand, MixJSON } else { + createDirs(dirOf(jsonCacheFileName)); + Path tmpFile = fmt("%s.tmp.%d", jsonCacheFileName, getpid()); - std::ofstream jsonCacheFile(tmpFile); + std::ofstream jsonCacheFile; - auto cache = writeCache ? std::make_unique(jsonCacheFile, false) : nullptr; + try { + // iostream considered harmful + jsonCacheFile.exceptions(std::ofstream::failbit); + jsonCacheFile.open(tmpFile); - doExpr(getSourceExpr(*state), "", true, cache.get()); + auto cache = writeCache ? std::make_unique(jsonCacheFile, false) : nullptr; + + doExpr(getSourceExpr(*state), "", true, cache.get()); + + } catch (std::exception &) { + /* Fun fact: catching std::ios::failure does not work + due to C++11 ABI shenanigans. + https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66145 */ + if (!jsonCacheFile) + throw Error("error writing to %s", tmpFile); + } if (rename(tmpFile.c_str(), jsonCacheFileName.c_str()) == -1) throw SysError("cannot rename '%s' to '%s'", tmpFile, jsonCacheFileName);