Merge pull request #332 from zevv/328

handle fwrite() errors more gracefully
zevv · Sep 4, 2024 · a58fa4e · a58fa4e
2 parents e66302f + 1b64bc4
commit a58fa4e
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Showing 3 changed files with 12 additions and 5 deletions.
diff --git a/src/duc/cmd-cgi.c b/src/duc/cmd-cgi.c
@@ -257,9 +257,11 @@ static void include_file(const char *fname)
  printf("<!-- start include -->\n");
  for(;;) {
  char buf[4096];
- size_t n = fread(buf, 1, sizeof(buf), f);
- if(n == 0) break;
- fwrite(buf, 1, n, stdout);
+ size_t in = fread(buf, 1, sizeof(buf), f);
+ if(in == 0) break;
+ size_t out = fwrite(buf, 1, in, stdout);
+ if(out == 0) break;
+ if(out < in) break;
  }
  printf("<!-- end include -->\n");
  fclose(f);

diff --git a/src/duc/main.c b/src/duc/main.c
@@ -211,6 +211,7 @@ static void printi(const char *s, int pos, int indent, int max)
  const char *p1 = s;
  const char *p2 = s;
  int i;
+ int out;
 
  while(*p1) {
  while(*p2 && !isspace(*p2)) p2++;
@@ -222,7 +223,8 @@ static void printi(const char *s, int pos, int indent, int max)
  pos = indent;
  }
 
- fwrite(p1, l, 1, stdout);
+ out = fwrite(p1, l, 1, stdout);
+ if (out == 0) break;
  while(*p2 && isspace(*p2)) p2++;
  pos += l;
  if(pos < max) {

diff --git a/src/libduc-graph/graph-cairo.c b/src/libduc-graph/graph-cairo.c
@@ -41,7 +41,10 @@ struct cairo_backend_data {
 static cairo_status_t cairo_writer(void *closure, const unsigned char *data, unsigned int length)
 {
  FILE *f = closure;
- fwrite(data, length, 1, f);
+ size_t out = fwrite(data, length, 1, f);
+ if (out == 0 || out < length) {
+ return CAIRO_STATUS_WRITE_ERROR;
+ }
  return CAIRO_STATUS_SUCCESS;
 }