(svn r26058) -Fix: handle the return value of a number of functions better

10 files changed, 53 insertions, 15 deletions

diff --git a/src/bmp.cpp b/src/bmp.cpp
index a93785d4f..2cb3dbf78 100644
--- a/src/bmp.cpp
+++ b/src/bmp.cpp
@@ -25,18 +25,24 @@ void BmpInitializeBuffer(BmpBuffer *buffer, FILE *file)
 
 static inline void AdvanceBuffer(BmpBuffer *buffer)
 {
+	if (buffer->read < 0) return;
+
 	buffer->read = (int)fread(buffer->data, 1, BMP_BUFFER_SIZE, buffer->file);
 	buffer->pos  = 0;
 }
 
 static inline bool EndOfBuffer(BmpBuffer *buffer)
 {
+	if (buffer->read < 0) return false;
+
 	if (buffer->pos == buffer->read || buffer->pos < 0) AdvanceBuffer(buffer);
 	return buffer->pos == buffer->read;
 }
 
 static inline byte ReadByte(BmpBuffer *buffer)
 {
+	if (buffer->read < 0) return 0;
+
 	if (buffer->pos == buffer->read || buffer->pos < 0) AdvanceBuffer(buffer);
 	buffer->real_pos++;
 	return buffer->data[buffer->pos++];
@@ -62,7 +68,9 @@ static inline void SkipBytes(BmpBuffer *buffer, int bytes)
 
 static inline void SetStreamOffset(BmpBuffer *buffer, int offset)
 {
-	fseek(buffer->file, offset, SEEK_SET);
+	if (fseek(buffer->file, offset, SEEK_SET) < 0) {
+		buffer->read = -1;
+	}
 	buffer->pos = -1;
 	buffer->real_pos = offset;
 	AdvanceBuffer(buffer);
diff --git a/src/debug.cpp b/src/debug.cpp
index d173ff14c..dceae7ec4 100644
--- a/src/debug.cpp
+++ b/src/debug.cpp
@@ -112,6 +112,8 @@ static void debug_print(const char *dbg, const char *buf)
 		char buf2[1024 + 32];
 
 		snprintf(buf2, lengthof(buf2), "%sdbg: [%s] %s\n", GetLogPrefix(), dbg, buf);
+		/* Sending out an error when this fails would be nice, however... the error
+		 * would have to be send over this failing socket which won't work. */
 		send(_debug_socket, buf2, (int)strlen(buf2), 0);
 		return;
 	}
diff --git a/src/fileio.cpp b/src/fileio.cpp
index 634033747..e17eaf654 100644
--- a/src/fileio.cpp
+++ b/src/fileio.cpp
@@ -88,7 +88,9 @@ void FioSeekTo(size_t pos, int mode)
 	if (mode == SEEK_CUR) pos += FioGetPos();
 	_fio.buffer = _fio.buffer_end = _fio.buffer_start + FIO_BUFFER_SIZE;
 	_fio.pos = pos;
-	fseek(_fio.cur_fh, _fio.pos, SEEK_SET);
+	if (fseek(_fio.cur_fh, _fio.pos, SEEK_SET) < 0) {
+		DEBUG(misc, 0, "Seeking in %s failed", _fio.filename);
+	}
 }
 
 #if defined(LIMITED_FDS)
@@ -450,7 +452,11 @@ FILE *FioFOpenFileTar(TarFileListEntry *entry, size_t *filesize)
 	FILE *f = fopen(entry->tar_filename, "rb");
 	if (f == NULL) return f;
 
-	fseek(f, entry->position, SEEK_SET);
+	if (fseek(f, entry->position, SEEK_SET) < 0) {
+		fclose(f);
+		return NULL;
+	}
+
 	if (filesize != NULL) *filesize = entry->size;
 	return f;
 }
@@ -533,6 +539,8 @@ FILE *FioFOpenFile(const char *filename, const char *mode, Subdirectory subdir,
  */
 static void FioCreateDirectory(const char *name)
 {
+	/* Ignore directory creation errors; they'll surface later on, and most
+	 * of the time they are 'directory already exists' errors anyhow. */
 #if defined(WIN32) || defined(WINCE)
 	CreateDirectory(OTTD2FS(name), NULL);
 #elif defined(OS2) && !defined(__INNOTEK_LIBC__)
@@ -897,7 +905,11 @@ bool TarScanner::AddFile(const char *filename, size_t basepath_length, const cha
 
 		/* Skip to the next block.. */
 		skip = Align(skip, 512);
-		fseek(f, skip, SEEK_CUR);
+		if (fseek(f, skip, SEEK_CUR) < 0) {
+			DEBUG(misc, 0, "The file '%s' can't be read as a valid tar-file", filename);
+			fclose(f);
+			return false;
+		}
 		pos += skip;
 	}
 
diff --git a/src/ini.cpp b/src/ini.cpp
index e82daaceb..11f79ed16 100644
--- a/src/ini.cpp
+++ b/src/ini.cpp
@@ -106,7 +106,9 @@ bool IniFile::SaveToDisk(const char *filename)
 	shfopt.pTo    = tfilename;
 	SHFileOperation(&shfopt);
 #else
-	rename(file_new, filename);
+	if (rename(file_new, filename) < 0) {
+		DEBUG(misc, 0, "Renaming %s to %s failed; configuration not saved", file_new, filename);
+	}
 #endif
 
 	return true;
diff --git a/src/newgrf_config.cpp b/src/newgrf_config.cpp
index 5ac8ba4df..bbd670a71 100644
--- a/src/newgrf_config.cpp
+++ b/src/newgrf_config.cpp
@@ -362,7 +362,11 @@ static bool CalcGRFMD5Sum(GRFConfig *config, Subdirectory subdir)
 
 	size_t start = ftell(f);
 	size = min(size, GRFGetSizeOfDataSection(f));
-	fseek(f, start, SEEK_SET);
+
+	if (fseek(f, start, SEEK_SET) < 0) {
+		FioFCloseFile(f);
+		return false;
+	}
 
 	/* calculate md5sum */
 	while ((len = fread(buffer, 1, (size > sizeof(buffer)) ? sizeof(buffer) : size, f)) != 0 && size != 0) {
diff --git a/src/pathfinder/yapf/yapf_node_rail.hpp b/src/pathfinder/yapf/yapf_node_rail.hpp
index 4950b2d29..b615b8227 100644
--- a/src/pathfinder/yapf/yapf_node_rail.hpp
+++ b/src/pathfinder/yapf/yapf_node_rail.hpp
@@ -196,7 +196,7 @@ struct CYapfRailNodeT
 		while (cur != GetLastTile() || cur_td != GetLastTrackdir()) {
 			if (!((obj.*func)(cur, cur_td))) return false;
 
-			ft.Follow(cur, cur_td);
+			if (!ft.Follow(cur, cur_td)) break;
 			cur = ft.m_new_tile;
 			assert(KillFirstBit(ft.m_new_td_bits) == TRACKDIR_BIT_NONE);
 			cur_td = FindFirstTrackdir(ft.m_new_td_bits);
diff --git a/src/saveload/oldloader.cpp b/src/saveload/oldloader.cpp
index f6ebb48bc..ff911a899 100644
--- a/src/saveload/oldloader.cpp
+++ b/src/saveload/oldloader.cpp
@@ -250,10 +250,9 @@ static SavegameType DetermineOldSavegameType(FILE *f, char *title, const char *l
 
 	/* Can't fseek to 0 as in tar files that is not correct */
 	long pos = ftell(f);
-	if (!CheckOldSavegameType(f, temp, lastof(temp), TTO_HEADER_SIZE)) {
+	if (pos >= 0 && !CheckOldSavegameType(f, temp, lastof(temp), TTO_HEADER_SIZE)) {
 		type = SGT_TTD;
-		fseek(f, pos, SEEK_SET);
-		if (!CheckOldSavegameType(f, temp, lastof(temp), TTD_HEADER_SIZE)) {
+		if (fseek(f, pos, SEEK_SET) < 0 || !CheckOldSavegameType(f, temp, lastof(temp), TTD_HEADER_SIZE)) {
 			type = SGT_INVALID;
 		}
 	}
diff --git a/src/saveload/saveload.cpp b/src/saveload/saveload.cpp
index 4bffa40c7..dc63abe5b 100644
--- a/src/saveload/saveload.cpp
+++ b/src/saveload/saveload.cpp
@@ -1848,7 +1848,9 @@ struct FileReader : LoadFilter {
 	/* virtual */ void Reset()
 	{
 		clearerr(this->file);
-		fseek(this->file, this->begin, SEEK_SET);
+		if (fseek(this->file, this->begin, SEEK_SET)) {
+			DEBUG(sl, 1, "Could not reset the file reading");
+		}
 	}
 };
 
diff --git a/src/script/squirrel.cpp b/src/script/squirrel.cpp
index 7c684d4b8..89b0b5625 100644
--- a/src/script/squirrel.cpp
+++ b/src/script/squirrel.cpp
@@ -493,7 +493,12 @@ SQRESULT Squirrel::LoadFile(HSQUIRRELVM vm, const char *filename, SQBool printer
 				}
 				func = _io_file_lexfeed_UTF8;
 				break;
-			default: func = _io_file_lexfeed_ASCII; fseek(file, -2, SEEK_CUR); break; // ASCII
+			default: // ASCII
+				func = _io_file_lexfeed_ASCII;
+				if (fseek(file, -2, SEEK_CUR) < 0) {
+					return sq_throwerror(vm, _SC("cannot read the file"));
+				}
+				break;
 		}
 
 		if (SQ_SUCCEEDED(sq_compile(vm, func, &f, OTTD2SQ(filename), printerror))) {
diff --git a/src/strgen/strgen.cpp b/src/strgen/strgen.cpp
index 01eaed4cb..5d0453841 100644
--- a/src/strgen/strgen.cpp
+++ b/src/strgen/strgen.cpp
@@ -353,7 +353,9 @@ struct LanguageFileWriter : LanguageWriter, FileWriter {
 
 	void Finalise()
 	{
-		fputc(0, this->fh);
+		if (fputc(0, this->fh) == EOF) {
+			error("Could not write to %s", this->filename);
+		}
 		this->FileWriter::Finalise();
 	}
 
@@ -368,10 +370,12 @@ struct LanguageFileWriter : LanguageWriter, FileWriter {
 /** Multi-OS mkdirectory function */
 static inline void ottd_mkdir(const char *directory)
 {
+	/* Ignore directory creation errors; they'll surface later on, and most
+	 * of the time they are 'directory already exists' errors anyhow. */
 #if defined(WIN32) || defined(__WATCOMC__)
-		mkdir(directory);
+	mkdir(directory);
 #else
-		mkdir(directory, 0755);
+	mkdir(directory, 0755);
 #endif
 }