From 895a74a814cd67cd2e13d0621603583a2d15b159 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Tue, 21 Mar 2017 19:23:07 +0100
Subject: [PATCH] LocalFSStore::getBuildLog(): Handle corrupted logs

---
 src/libstore/local-fs-store.cc |  9 +++++++--
 src/libutil/compression.cc     | 24 ++++++++++++------------
 src/libutil/compression.hh     |  2 ++
 3 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/src/libstore/local-fs-store.cc b/src/libstore/local-fs-store.cc
index 002ee4a65..57e1b8a09 100644
--- a/src/libstore/local-fs-store.cc
+++ b/src/libstore/local-fs-store.cc
@@ -94,6 +94,7 @@ std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path & path_)
 
     assertStorePath(path);
 
+
     if (!isDerivation(path)) {
         try {
             path = queryPathInfo(path)->deriver;
@@ -116,8 +117,12 @@ std::shared_ptr<std::string> LocalFSStore::getBuildLog(const Path & path_)
         if (pathExists(logPath))
             return std::make_shared<std::string>(readFile(logPath));
 
-        else if (pathExists(logBz2Path))
-            return decompress("bzip2", readFile(logBz2Path));
+        else if (pathExists(logBz2Path)) {
+            try {
+                return decompress("bzip2", readFile(logBz2Path));
+            } catch (Error &) { }
+        }
+
     }
 
     return nullptr;
diff --git a/src/libutil/compression.cc b/src/libutil/compression.cc
index 11eec7a7b..f913d0f5b 100644
--- a/src/libutil/compression.cc
+++ b/src/libutil/compression.cc
@@ -18,7 +18,7 @@ static ref<std::string> decompressXZ(const std::string & in)
     lzma_ret ret = lzma_stream_decoder(
         &strm, UINT64_MAX, LZMA_CONCATENATED);
     if (ret != LZMA_OK)
-        throw Error("unable to initialise lzma decoder");
+        throw CompressionError("unable to initialise lzma decoder");
 
     Finally free([&]() { lzma_end(&strm); });
 
@@ -48,10 +48,10 @@ static ref<std::string> decompressXZ(const std::string & in)
             return res;
 
         if (ret != LZMA_OK)
-            throw Error("error while decompressing xz file");
+            throw CompressionError("error while decompressing xz file");
 
         if (strm.avail_in == 0)
-            throw Error("xz data ends prematurely");
+            throw CompressionError("xz data ends prematurely");
     }
 }
 
@@ -62,7 +62,7 @@ static ref<std::string> decompressBzip2(const std::string & in)
 
     int ret = BZ2_bzDecompressInit(&strm, 0, 0);
     if (ret != BZ_OK)
-        throw Error("unable to initialise bzip2 decoder");
+        throw CompressionError("unable to initialise bzip2 decoder");
 
     Finally free([&]() { BZ2_bzDecompressEnd(&strm); });
 
@@ -88,10 +88,10 @@ static ref<std::string> decompressBzip2(const std::string & in)
             return res;
 
         if (ret != BZ_OK)
-            throw Error("error while decompressing bzip2 file");
+            throw CompressionError("error while decompressing bzip2 file");
 
         if (strm.avail_in == 0)
-            throw Error("bzip2 data ends prematurely");
+            throw CompressionError("bzip2 data ends prematurely");
     }
 }
 
@@ -144,7 +144,7 @@ struct XzSink : CompressionSink
         lzma_ret ret = lzma_easy_encoder(
             &strm, 6, LZMA_CHECK_CRC64);
         if (ret != LZMA_OK)
-            throw Error("unable to initialise lzma encoder");
+            throw CompressionError("unable to initialise lzma encoder");
         // FIXME: apply the x86 BCJ filter?
 
         strm.next_out = outbuf;
@@ -168,7 +168,7 @@ struct XzSink : CompressionSink
 
             lzma_ret ret = lzma_code(&strm, LZMA_FINISH);
             if (ret != LZMA_OK && ret != LZMA_STREAM_END)
-                throw Error("error while flushing xz file");
+                throw CompressionError("error while flushing xz file");
 
             if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
                 nextSink(outbuf, sizeof(outbuf) - strm.avail_out);
@@ -192,7 +192,7 @@ struct XzSink : CompressionSink
 
             lzma_ret ret = lzma_code(&strm, LZMA_RUN);
             if (ret != LZMA_OK)
-                throw Error("error while compressing xz file");
+                throw CompressionError("error while compressing xz file");
 
             if (strm.avail_out == 0) {
                 nextSink(outbuf, sizeof(outbuf));
@@ -215,7 +215,7 @@ struct BzipSink : CompressionSink
         memset(&strm, 0, sizeof(strm));
         int ret = BZ2_bzCompressInit(&strm, 9, 0, 30);
         if (ret != BZ_OK)
-            throw Error("unable to initialise bzip2 encoder");
+            throw CompressionError("unable to initialise bzip2 encoder");
 
         strm.next_out = outbuf;
         strm.avail_out = sizeof(outbuf);
@@ -238,7 +238,7 @@ struct BzipSink : CompressionSink
 
             int ret = BZ2_bzCompress(&strm, BZ_FINISH);
             if (ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
-                throw Error("error while flushing bzip2 file");
+                throw CompressionError("error while flushing bzip2 file");
 
             if (strm.avail_out == 0 || ret == BZ_STREAM_END) {
                 nextSink((unsigned char *) outbuf, sizeof(outbuf) - strm.avail_out);
@@ -262,7 +262,7 @@ struct BzipSink : CompressionSink
 
             int ret = BZ2_bzCompress(&strm, BZ_RUN);
             if (ret != BZ_OK)
-                Error("error while compressing bzip2 file");
+                CompressionError("error while compressing bzip2 file");
 
             if (strm.avail_out == 0) {
                 nextSink((unsigned char *) outbuf, sizeof(outbuf));
diff --git a/src/libutil/compression.hh b/src/libutil/compression.hh
index eacf559d6..e3e6f5a99 100644
--- a/src/libutil/compression.hh
+++ b/src/libutil/compression.hh
@@ -21,4 +21,6 @@ ref<CompressionSink> makeCompressionSink(const std::string & method, Sink & next
 
 MakeError(UnknownCompressionMethod, Error);
 
+MakeError(CompressionError, Error);
+
 }