main: Add error checks and comments

k-takata · Aug 23, 2015 · 690fa22 · 690fa22 · masatake · Aug 23, 2015
1 parent ef6c3af
commit 690fa22
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/main/entry.c b/main/entry.c
@@ -414,6 +414,8 @@ extern void openTagFile (void)
 	/*  Open the tags file.
 	 */
 	if (TagsToStdout)
+		/* Open a tempfile with read and write mode. Read mode is used when
+		 * write the result to stdout. */
 		TagFile.fp = tempFile ("w+", &TagFile.name);
 	else
 	{
@@ -548,12 +550,13 @@ extern void closeTagFile (const boolean resize)
 
 	if (Option.etags)
 		writeEtagsIncludes (TagFile.fp);
-	abort_if_ferror (TagFile.fp);
 	fflush (TagFile.fp);
+	abort_if_ferror (TagFile.fp);
 	desiredSize = ftell (TagFile.fp);
 	fseek (TagFile.fp, 0L, SEEK_END);
 	size = ftell (TagFile.fp);
 	if (! TagsToStdout)
+		/* The tag file should be closed before resizing. */
 		if (fclose (TagFile.fp) != 0)
 			error (FATAL | PERROR, "cannot close tag file");
 

diff --git a/main/sort.c b/main/sort.c
@@ -99,10 +99,15 @@ extern void externalSortTags (const boolean toStdout)
 			int fdsave;
 
 			fdsave = dup (fdstdin);
-			dup2 (fileno (TagFile.fp), fdstdin);
-			lseek (fdstdin, 0, SEEK_SET);
+			if (fdsave < 0)
+				error (FATAL | PERROR, "cannot save stdin fd");
+			if (dup2 (fileno (TagFile.fp), fdstdin) < 0)
+				error (FATAL | PERROR, "cannot redirect stdin");
+			if (lseek (fdstdin, 0, SEEK_SET) != 0)
+				error (FATAL | PERROR, "cannot rewind tag file");
 			ret = system (cmd);
-			dup2 (fdsave, fdstdin);
+			if (dup2 (fdsave, fdstdin) < 0)
+				error (FATAL | PERROR, "cannot restore stdin fd");
 			close (fdsave);
 		}
 		else