Fixed : default sparse mode disabled on stdout, to support ` >>` redirection scenario reported by Takayuki Matsuoka (#110)

3 files changed, 20 insertions, 10 deletions

diff --git a/programs/Makefile b/programs/Makefile
index f015d27..43f1789 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -171,6 +171,18 @@ test-lz4-sparse: lz4 datagen
 	echo "Hello World 1 !" | ./lz4 | ./lz4 -d -c
 	echo "Hello World 2 !" | ./lz4 | ./lz4 -d | cat
 	echo "Hello World 3 !" | ./lz4 --no-frame-crc | ./lz4 -d -c
+	@echo "\n Compatibility with Append :"
+	./datagen -P100 -g1M > tmp1M
+	cat tmp1M > tmp2M
+	cat tmp1M >> tmp2M
+	./lz4 -B5 -v tmp1M tmpC
+	./lz4 -d -v tmpC tmpR
+	./lz4 -d -v tmpC >> tmpR
+	ls -ls tmp*
+	diff tmp2M tmpR
+	@rm tmp*
+
+
 
 test-lz4-contentSize: lz4 datagen
 	@echo "\n ---- test original size support ----"
diff --git a/programs/lz4cli.c b/programs/lz4cli.c
index 65af428..e5210c9 100644
--- a/programs/lz4cli.c
+++ b/programs/lz4cli.c
@@ -306,7 +306,7 @@ int main(int argc, char** argv)
         if (!strcmp(argument, "--no-frame-crc")) { LZ4IO_setStreamChecksumMode(0); continue; }
         if (!strcmp(argument, "--content-size")) { LZ4IO_setContentSize(1); continue; }
         if (!strcmp(argument, "--no-content-size")) { LZ4IO_setContentSize(0); continue; }
-        if (!strcmp(argument, "--sparse")) { LZ4IO_setSparseFile(1); continue; }
+        if (!strcmp(argument, "--sparse")) { LZ4IO_setSparseFile(2); continue; }
         if (!strcmp(argument, "--no-sparse")) { LZ4IO_setSparseFile(0); continue; }
         if (!strcmp(argument, "--verbose")) { displayLevel=4; continue; }
         if (!strcmp(argument, "--quiet")) { if (displayLevel) displayLevel--; continue; }
diff --git a/programs/lz4io.c b/programs/lz4io.c
index dc0b9ec..e782664 100644
--- a/programs/lz4io.c
+++ b/programs/lz4io.c
@@ -278,6 +278,11 @@ static int LZ4IO_getFiles(const char* input_filename, const char* output_filenam
         DISPLAYLEVEL(4,"Using stdout for output\n");
         *pfoutput = stdout;
         SET_BINARY_MODE(stdout);
+        if (g_sparseFileSupport==1)
+        {
+            g_sparseFileSupport = 0;
+            DISPLAYLEVEL(4, "Sparse File Support is automatically disabled on stdout ; try --sparse \n");
+        }
     }
     else
     {
@@ -303,13 +308,6 @@ static int LZ4IO_getFiles(const char* input_filename, const char* output_filenam
 
     if (*pfoutput==0) EXM_THROW(13, "Pb opening %s", output_filename);
 
-    if (g_sparseFileSupport)
-    {
-        long int ftr = ftell(*pfoutput);
-        /* DISPLAY("%s->%s ==> %i \n", input_filename, output_filename, (int)ftr); */
-        if (ftr!=0) g_sparseFileSupport = 0;
-    }
-
     return 0;
 }
 
@@ -674,7 +672,7 @@ static unsigned LZ4IO_fwriteSparse(FILE* file, const void* buffer, size_t buffer
         {
             size_t sizeCheck;
             seekResult = fseek(file, storedSkips, SEEK_CUR);
-            if (seekResult) EXM_THROW(72, "Skip error (sparse file)");
+            if (seekResult) EXM_THROW(72, "Sparse skip error ; try --no-sparse");
             storedSkips = 0;
             seg0SizeT -= nb0T;
             ptrT += nb0T;
@@ -696,7 +694,7 @@ static unsigned LZ4IO_fwriteSparse(FILE* file, const void* buffer, size_t buffer
         {
             size_t sizeCheck;
             int seekResult = fseek(file, storedSkips, SEEK_CUR);
-            if (seekResult) EXM_THROW(74, "Skip error (end of block)");
+            if (seekResult) EXM_THROW(74, "Sparse skip error ; try --no-sparse");
             storedSkips = 0;
             sizeCheck = fwrite(restPtr, 1, restEnd - restPtr, file);
             if (sizeCheck != (size_t)(restEnd - restPtr)) EXM_THROW(75, "Write error : cannot write decoded end of block");