patch: fix vda's thinko: we need to open new_filename.orig, always!

plug memory leak; add testsuite

patch_main                                          1009     988     -21

2 files changed, 59 insertions, 18 deletions

diff --git a/editors/patch.c b/editors/patch.c
index 7b391603d..2a2b130b9 100644
--- a/editors/patch.c
+++ b/editors/patch.c
@@ -87,7 +87,7 @@ int patch_main(int argc ATTRIBUTE_UNUSED, char **argv)
         while (patch_line) {
                 FILE *src_stream;
                 FILE *dst_stream;
-                char *original_filename;
+                //char *old_filename;
                 char *new_filename;
                 char *backup_filename;
                 unsigned src_cur_line = 1;
@@ -102,10 +102,12 @@ int patch_main(int argc ATTRIBUTE_UNUSED, char **argv)
                  */
                 do {
                         /* Extract the filename used before the patch was generated */
-                        original_filename = extract_filename(patch_line, patch_level, "--- ");
+                        new_filename = extract_filename(patch_line, patch_level, "--- ");
+                        // was old_filename above
                         patch_line = xmalloc_getline(patch_file);
                         if (!patch_line) goto quit;
-                } while (!original_filename);
+                } while (!new_filename);
+                free(new_filename); // "source" filename is irrelevant
 
                 new_filename = extract_filename(patch_line, patch_level, "+++ ");
                 if (!new_filename) {
@@ -122,25 +124,15 @@ int patch_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                 *slash = '/';
                         }
                         backup_filename = NULL;
+                        src_stream = NULL;
                         saved_stat.st_mode = 0644;
                 } else {
                         backup_filename = xasprintf("%s.orig", new_filename);
                         xrename(new_filename, backup_filename);
+                        src_stream = xfopen(backup_filename, "r");
                 }
                 dst_stream = xfopen(new_filename, "w");
                 fchmod(fileno(dst_stream), saved_stat.st_mode);
-                src_stream = NULL;
-                if (backup_filename && stat(original_filename, &saved_stat) == 0) {
-                        // strcmp() is never 0! Otherwise:
-                        // original_filename == new_filename,
-                        // stat(original_filename) == stat(new_filename),
-                        // stat(new_filename) == 0,
-                        // but we renamed new_filename if it existed!
-                        // stat() must fail!
-                        //src_stream = xfopen((strcmp(original_filename, new_filename)) ?
-                        //                      original_filename : backup_filename, "r");
-                        src_stream = xfopen(original_filename, "r");
-                }
 
                 printf("patching file %s\n", new_filename);
 
@@ -224,15 +216,17 @@ int patch_main(int argc ATTRIBUTE_UNUSED, char **argv)
                         /* It worked, we can remove the backup */
                         if (backup_filename) {
                                 unlink(backup_filename);
-                                free(backup_filename);
                         }
                         if ((dest_cur_line == 0) || (dest_beg_line == 0)) {
                                 /* The new patched file is empty, remove it */
                                 xunlink(new_filename);
-                                /* original_filename and new_filename may be the same file */
-                                unlink(original_filename);
+                                // /* old_filename and new_filename may be the same file */
+                                // unlink(old_filename);
                         }
                 }
+                free(backup_filename);
+                //free(old_filename);
+                free(new_filename);
         } /* end of "while there are patch lines" */
 quit:
 
diff --git a/testsuite/patch.tests b/testsuite/patch.tests
new file mode 100755
index 000000000..8a957d3f7
--- /dev/null
+++ b/testsuite/patch.tests
@@ -0,0 +1,47 @@
+#!/bin/sh
+# Copyright 2008 by Denys Vlasenko
+# Licensed under GPL v2, see file LICENSE for details.
+
+. testing.sh
+
+# testing "test name" "options" "expected result" "file input" "stdin"
+
+testing "patch with old_file == new_file" \
+        "patch; echo $?; cat input" \
+"\
+patching file input
+0
+qwe
+asd
+zxc
+" \
+        "qwe\nzxc\n" \
+"\
+--- input       Jan 01 01:01:01 2000
++++ input       Jan 01 01:01:01 2000
+@@ -1,2 +1,3 @@
+ qwe
++asd
+ zxc
+" \
+
+testing "patch with nonexistent old_file" \
+        "strace -o zzz patch; echo $?; cat input" \
+"\
+patching file input
+0
+qwe
+asd
+zxc
+" \
+        "qwe\nzxc\n" \
+"\
+--- input.doesnt_exist  Jan 01 01:01:01 2000
++++ input       Jan 01 01:01:01 2000
+@@ -1,2 +1,3 @@
+ qwe
++asd
+ zxc
+" \
+
+exit $FAILCOUNT