pngminus: Delete the incomplete output files upon premature termination
Defer the program termination on error until all files are closed and
(if applicable) all incompletely-written output files are deleted.
In addition, perform the following maintenance tasks:
* Rename and document the internal helpers used by the functions
`png2pnm` and `pnm2png`.
* Unset the executable permission bits for the *.bat test programs.
diff --git a/contrib/pngminus/CHANGES.txt b/contrib/pngminus/CHANGES.txt
index 2001f31..85e590a 100644
--- a/contrib/pngminus/CHANGES.txt
+++ b/contrib/pngminus/CHANGES.txt
@@ -11,4 +11,4 @@
1.5 - 2018.08.05 - Fix buffer overflow in tokenizer (Cosmin Truta)
1.6 - 2018.08.05 - Improve portability and fix style (Cosmin Truta)
1.7 - 2019.01.22 - Change license to MIT (Willem van Schaik)
- 1.8 - 2024.01.08 - Fix, improve, modernize (Cosmin Truta)
+ 1.8 - 2024.01.09 - Fix, improve, modernize (Cosmin Truta)
diff --git a/contrib/pngminus/png2pnm.c b/contrib/pngminus/png2pnm.c
index bb159e2..f9d5138 100644
--- a/contrib/pngminus/png2pnm.c
+++ b/contrib/pngminus/png2pnm.c
@@ -28,9 +28,9 @@
void usage ();
BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
BOOL raw, BOOL alpha);
-BOOL png2pnm_internal (png_struct *png_ptr, png_info *info_ptr,
- FILE *pnm_file, FILE *alpha_file,
- BOOL raw, BOOL alpha);
+BOOL do_png2pnm (png_struct *png_ptr, png_info *info_ptr,
+ FILE *pnm_file, FILE *alpha_file,
+ BOOL raw, BOOL alpha);
/*
* main
@@ -41,9 +41,12 @@
FILE *fp_rd = stdin;
FILE *fp_wr = stdout;
FILE *fp_al = NULL;
+ const char *fname_wr = NULL;
+ const char *fname_al = NULL;
BOOL raw = TRUE;
BOOL alpha = FALSE;
int argi;
+ int ret;
for (argi = 1; argi < argc; argi++)
{
@@ -62,6 +65,7 @@
argi++;
if ((fp_al = fopen (argv[argi], "wb")) == NULL)
{
+ fname_al = argv[argi];
fprintf (stderr, "PNM2PNG\n");
fprintf (stderr, "Error: cannot create alpha-channel file %s\n",
argv[argi]);
@@ -92,6 +96,7 @@
}
else if (fp_wr == stdout)
{
+ fname_wr = argv[argi];
if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
{
fprintf (stderr, "PNG2PNM\n");
@@ -117,12 +122,7 @@
#endif
/* call the conversion program itself */
- if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
- {
- fprintf (stderr, "PNG2PNM\n");
- fprintf (stderr, "Error: unsuccessful conversion of PNG-image\n");
- exit (1);
- }
+ ret = png2pnm (fp_rd, fp_wr, fp_al, raw, alpha);
/* close input file */
fclose (fp_rd);
@@ -132,6 +132,17 @@
if (alpha)
fclose (fp_al);
+ if (!ret)
+ {
+ fprintf (stderr, "PNG2PNM\n");
+ fprintf (stderr, "Error: unsuccessful conversion of PNG-image\n");
+ if (fname_wr)
+ remove (fname_wr); /* no broken output file shall remain behind */
+ if (fname_al)
+ remove (fname_al); /* ditto */
+ exit (1);
+ }
+
return 0;
}
@@ -165,7 +176,7 @@
png_info *info_ptr;
BOOL ret;
- /* initialize the libpng structures for reading from png_file */
+ /* initialize the libpng context for reading from png_file */
png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
NULL, NULL, NULL);
@@ -188,7 +199,7 @@
png_init_io (png_ptr, png_file);
/* do the actual conversion */
- ret = png2pnm_internal (png_ptr, info_ptr, pnm_file, alpha_file, raw, alpha);
+ ret = do_png2pnm (png_ptr, info_ptr, pnm_file, alpha_file, raw, alpha);
/* clean up the libpng structures and their internally-managed data */
png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
@@ -197,12 +208,12 @@
}
/*
- * png2pnm_internal
+ * do_png2pnm - does the conversion in a fully-initialized libpng context
*/
-BOOL png2pnm_internal (png_struct *png_ptr, png_info *info_ptr,
- FILE *pnm_file, FILE *alpha_file,
- BOOL raw, BOOL alpha)
+BOOL do_png2pnm (png_struct *png_ptr, png_info *info_ptr,
+ FILE *pnm_file, FILE *alpha_file,
+ BOOL raw, BOOL alpha)
{
png_byte **row_pointers;
png_byte *pix_ptr;
diff --git a/contrib/pngminus/pnm2png.c b/contrib/pngminus/pnm2png.c
index b89b732..052fd32 100644
--- a/contrib/pngminus/pnm2png.c
+++ b/contrib/pngminus/pnm2png.c
@@ -29,9 +29,9 @@
void usage ();
BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file,
BOOL interlace, BOOL alpha);
-BOOL pnm2png_internal (png_struct *png_ptr, png_info *info_ptr,
- FILE *pnm_file, FILE *alpha_file,
- BOOL interlace, BOOL alpha);
+BOOL do_pnm2png (png_struct *png_ptr, png_info *info_ptr,
+ FILE *pnm_file, FILE *alpha_file,
+ BOOL interlace, BOOL alpha);
int fscan_pnm_magic (FILE *pnm_file, char *magic_buf, size_t magic_buf_size);
int fscan_pnm_token (FILE *pnm_file, char *token_buf, size_t token_buf_size);
int fscan_pnm_uint_32 (FILE *pnm_file, png_uint_32 *num_ptr);
@@ -47,9 +47,11 @@
FILE *fp_rd = stdin;
FILE *fp_al = NULL;
FILE *fp_wr = stdout;
+ const char *fname_wr = NULL;
BOOL interlace = FALSE;
BOOL alpha = FALSE;
int argi;
+ int ret;
for (argi = 1; argi < argc; argi++)
{
@@ -95,6 +97,7 @@
}
else if (fp_wr == stdout)
{
+ fname_wr = argv[argi];
if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
{
fprintf (stderr, "PNM2PNG\n");
@@ -122,12 +125,7 @@
#endif
/* call the conversion program itself */
- if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
- {
- fprintf (stderr, "PNM2PNG\n");
- fprintf (stderr, "Error: unsuccessful converting to PNG-image\n");
- exit (1);
- }
+ ret = pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha);
/* close input file */
fclose (fp_rd);
@@ -137,6 +135,15 @@
if (alpha)
fclose (fp_al);
+ if (!ret)
+ {
+ fprintf (stderr, "PNM2PNG\n");
+ fprintf (stderr, "Error: unsuccessful converting to PNG-image\n");
+ if (fname_wr)
+ remove (fname_wr); /* no broken output file shall remain behind */
+ exit (1);
+ }
+
return 0;
}
@@ -168,7 +175,7 @@
png_info *info_ptr;
BOOL ret;
- /* initialize the libpng structures for writing to png_file */
+ /* initialize the libpng context for writing to png_file */
png_ptr = png_create_write_struct (png_get_libpng_ver(NULL),
NULL, NULL, NULL);
@@ -191,8 +198,7 @@
png_init_io (png_ptr, png_file);
/* do the actual conversion */
- ret = pnm2png_internal (png_ptr, info_ptr,
- pnm_file, alpha_file, interlace, alpha);
+ ret = do_pnm2png (png_ptr, info_ptr, pnm_file, alpha_file, interlace, alpha);
/* clean up the libpng structures and their internally-managed data */
png_destroy_write_struct (&png_ptr, &info_ptr);
@@ -201,12 +207,12 @@
}
/*
- * pnm2png_internal
+ * do_pnm2png - does the conversion in a fully-initialized libpng context
*/
-BOOL pnm2png_internal (png_struct *png_ptr, png_info *info_ptr,
- FILE *pnm_file, FILE *alpha_file,
- BOOL interlace, BOOL alpha)
+BOOL do_pnm2png (png_struct *png_ptr, png_info *info_ptr,
+ FILE *pnm_file, FILE *alpha_file,
+ BOOL interlace, BOOL alpha)
{
png_byte **row_pointers;
png_byte *pix_ptr;
diff --git a/contrib/pngminus/test_png2pnm.bat b/contrib/pngminus/test_png2pnm.bat
old mode 100755
new mode 100644
diff --git a/contrib/pngminus/test_pnm2png.bat b/contrib/pngminus/test_pnm2png.bat
old mode 100755
new mode 100644
