# HG changeset patch
# User Michael Witten <mfwitten@gmail.com>
# Date 1475887737 0
#      Sat Oct 08 00:48:57 2016 +0000
# Branch 2.7
# Node ID feecb6c8609b395ca8781608b85d45e25c4087f7
# Parent  59260b38f7cd4a2ae66928de5227798524006e64
PEP 235: Extend to every POSIX system the case-sensitivity semantics for `import'

(Note: As per PEP 235, this explicit checking of case may be effectively
disabled by defining the environment variable `PYTHONCASEOK'.)

From time to time, even a user of a sane system has been known
[to be forced] to use an insane file system; the semantics of
PEP 235 need to be implemented in this case as well.

On a sane system, mount an insane file system at "$mount",
and then run this example:

  $ cd "$mount"
  $ touch Insane.py
  $ python -c 'import Insane; import insane; print(dir())'

Before this revision, the resulting output is:

  ['Insane', '__builtins__', '__doc__', '__name__', '__package__', 'insane']

After this commit, the resulting output is sane:

  Traceback (most recent call last):
  File "<string>", line 1, in <module>
  ImportError: No module named insane

Because POSIX systems may be a subset of sane systems, this is only
a partial fix to the overall problem; as much as possible, *every*
system should implement the same semantics.

diff -r 59260b38f7cd -r feecb6c8609b Python/import.c
--- a/Python/import.c	Wed Oct 05 23:26:24 2016 -0700
+++ b/Python/import.c	Sat Oct 08 00:48:57 2016 +0000
@@ -1666,7 +1666,7 @@
 #elif defined(DJGPP)
 #include <dir.h>
 
-#elif (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
+#elif _POSIX_C_SOURCE || (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
 #include <sys/types.h>
 #include <dirent.h>
 
@@ -1723,7 +1723,7 @@
     return strncmp(ffblk.ff_name, name, namelen) == 0;
 
 /* new-fangled macintosh (macosx) or Cygwin */
-#elif (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
+#elif _POSIX_C_SOURCE || (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
     DIR *dirp;
     struct dirent *dp;
     char dirname[MAXPATHLEN + 1];
# HG changeset patch
# User Michael Witten <mfwitten@gmail.com>
# Date 1475955396 0
#      Sat Oct 08 19:36:36 2016 +0000
# Branch 2.7
# Node ID cab072a518643e33d399b2e02a48a3419420c3ad
# Parent  feecb6c8609b395ca8781608b85d45e25c4087f7
PEP 235: Refactor each system-dependent implementation into its own function

This change is mostly a matter of aesthetic taste, but it does confer
a few technical benefits:

* There is now no longer a repitition of the same #if/#elif conditional
  compilations; there is no longer a need to maintain these repititions
  in the same order (a request which has been ignored, anyway).

* By being self-contained, each implementation is more comprehensible;
  for each one, there is a clear beginning and end.

* Macros have been used only in a way that deliberately preserves and
  explicitly employs the C-funtion construct; tools that analyze and
  search the source should be able to identify these functions easily
  without macro magic obscuring their meanings.

diff -r feecb6c8609b -r cab072a51864 Python/import.c
--- a/Python/import.c	Sat Oct 08 00:48:57 2016 +0000
+++ b/Python/import.c	Sat Oct 08 19:36:36 2016 +0000
@@ -1657,164 +1657,193 @@
  * nightmare for systems with case-insensitive filesystems.
  */
 
-/* First we may need a pile of platform-specific header files; the sequence
- * of #if's here should match the sequence in the body of case_ok().
- */
+#define CASE_OK_PARAMS char *buf, Py_ssize_t len, Py_ssize_t namelen, char *name
+#define CASE_OK_ARGS         buf,            len,            namelen,       name
+
 #if defined(MS_WINDOWS)
-#include <windows.h>
+
+    #define CASE_OK_IMP imp_ms_windows_case_ok
+
+    #include <windows.h>
+
+    static int
+    imp_ms_windows_case_ok(CASE_OK_PARAMS)
+    {
+        WIN32_FIND_DATA data;
+        HANDLE h;
+
+        if (Py_GETENV("PYTHONCASEOK") != NULL)
+            return 1;
+
+        h = FindFirstFile(buf, &data);
+        if (h == INVALID_HANDLE_VALUE) {
+            PyErr_Format(PyExc_NameError,
+              "Can't find file for module %.100s\n(filename %.300s)",
+              name, buf);
+            return 0;
+        }
+        FindClose(h);
+        return strncmp(data.cFileName, name, namelen) == 0;
+    }
 
 #elif defined(DJGPP)
-#include <dir.h>
+
+    #define CASE_OK_IMP imp_djgpp_case_ok
+
+    #include <dir.h>
+
+    static int
+    imp_djgpp_case_ok(CASE_OK_PARAMS)
+    {
+        struct ffblk ffblk;
+        int done;
+
+        if (Py_GETENV("PYTHONCASEOK") != NULL)
+            return 1;
+
+        done = findfirst(buf, &ffblk, FA_ARCH|FA_RDONLY|FA_HIDDEN|FA_DIREC);
+        if (done) {
+            PyErr_Format(PyExc_NameError,
+              "Can't find file for module %.100s\n(filename %.300s)",
+              name, buf);
+            return 0;
+        }
+        return strncmp(ffblk.ff_name, name, namelen) == 0;
+    }
 
 #elif _POSIX_C_SOURCE || (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
-#include <sys/types.h>
-#include <dirent.h>
+
+    #define CASE_OK_IMP imp_posix_case_ok
+
+    #ifdef _DIRENT_HAVE_D_NAMELEN
+        #define NAMLEN(dp) dp->d_namlen;
+    #else
+        #define NAMLEN(dp) strlen(dp->d_name);
+    #endif
+
+    #include <sys/types.h>
+    #include <dirent.h>
+
+    static int
+    imp_posix_case_ok(CASE_OK_PARAMS)
+    {
+        DIR *dirp;
+        struct dirent *dp;
+        char dirname[MAXPATHLEN + 1];
+        const int dirlen = len - namelen - 1; /* don't want trailing SEP */
+
+        if (Py_GETENV("PYTHONCASEOK") != NULL)
+            return 1;
+
+        /* Copy the dir component into dirname; substitute "." if empty */
+        if (dirlen <= 0) {
+            dirname[0] = '.';
+            dirname[1] = '\0';
+        }
+        else {
+            assert(dirlen <= MAXPATHLEN);
+            memcpy(dirname, buf, dirlen);
+            dirname[dirlen] = '\0';
+        }
+        /* Open the directory and search the entries for an exact match. */
+        dirp = opendir(dirname);
+        if (dirp) {
+            char *nameWithExt = buf + len - namelen;
+            while ((dp = readdir(dirp)) != NULL) {
+                const int thislen = NAMLEN(dp);
+                if (thislen >= namelen &&
+                    strcmp(dp->d_name, nameWithExt) == 0) {
+                    (void)closedir(dirp);
+                    return 1; /* Found */
+                }
+            }
+            (void)closedir(dirp);
+        }
+        return 0 ; /* Not found */
+    }
 
 #elif defined(PYOS_OS2)
-#define INCL_DOS
-#define INCL_DOSERRORS
-#define INCL_NOPMAPI
-#include <os2.h>
+
+    #define CASE_OK_IMP imp_os2_case_ok
+
+    #define INCL_DOS
+    #define INCL_DOSERRORS
+    #define INCL_NOPMAPI
+    #include <os2.h>
+
+    static int
+    imp_os2_case_ok(CASE_OK_PARAMS)
+    {
+        HDIR hdir = 1;
+        ULONG srchcnt = 1;
+        FILEFINDBUF3 ffbuf;
+        APIRET rc;
+
+        if (Py_GETENV("PYTHONCASEOK") != NULL)
+            return 1;
+
+        rc = DosFindFirst(buf,
+                          &hdir,
+                          FILE_READONLY | FILE_HIDDEN | FILE_SYSTEM | FILE_DIRECTORY,
+                          &ffbuf, sizeof(ffbuf),
+                          &srchcnt,
+                          FIL_STANDARD);
+        if (rc != NO_ERROR)
+            return 0;
+        return strncmp(ffbuf.achName, name, namelen) == 0;
+    }
 
 #elif defined(RISCOS)
-#include "oslib/osfscontrol.h"
+
+    #define CASE_OK_IMP imp_riscos_case_ok
+
+    #include "oslib/osfscontrol.h"
+
+    static int
+    imp_riscos_case_ok(CASE_OK_PARAMS)
+    {
+        char canon[MAXPATHLEN+1]; /* buffer for the canonical form of the path */
+        char buf2[MAXPATHLEN+2];
+        char *nameWithExt = buf+len-namelen;
+        int canonlen;
+        os_error *e;
+
+        if (Py_GETENV("PYTHONCASEOK") != NULL)
+            return 1;
+
+        /* workaround:
+           append wildcard, otherwise case of filename wouldn't be touched */
+        strcpy(buf2, buf);
+        strcat(buf2, "*");
+
+        e = xosfscontrol_canonicalise_path(buf2,canon,0,0,MAXPATHLEN+1,&canonlen);
+        canonlen = MAXPATHLEN+1-canonlen;
+        if (e || canonlen<=0 || canonlen>(MAXPATHLEN+1) )
+            return 0;
+        if (strcmp(nameWithExt, canon+canonlen-strlen(nameWithExt))==0)
+            return 1; /* match */
+
+        return 0;
+    }
+
+#else
+
+    #define CASE_OK_IMP imp_default_case_ok
+
+    static int
+    imp_default_case_ok(CASE_OK_PARAMS)
+    {
+        return 1;
+    }
+
 #endif
 
 static int
+case_ok(CASE_OK_PARAMS)
+{
+    return CASE_OK_IMP(CASE_OK_ARGS);
+}
-case_ok(char *buf, Py_ssize_t len, Py_ssize_t namelen, char *name)
-{
-/* Pick a platform-specific implementation; the sequence of #if's here should
- * match the sequence just above.
- */
-
-/* MS_WINDOWS */
-#if defined(MS_WINDOWS)
-    WIN32_FIND_DATA data;
-    HANDLE h;
-
-    if (Py_GETENV("PYTHONCASEOK") != NULL)
-        return 1;
-
-    h = FindFirstFile(buf, &data);
-    if (h == INVALID_HANDLE_VALUE) {
-        PyErr_Format(PyExc_NameError,
-          "Can't find file for module %.100s\n(filename %.300s)",
-          name, buf);
-        return 0;
-    }
-    FindClose(h);
-    return strncmp(data.cFileName, name, namelen) == 0;
-
-/* DJGPP */
-#elif defined(DJGPP)
-    struct ffblk ffblk;
-    int done;
-
-    if (Py_GETENV("PYTHONCASEOK") != NULL)
-        return 1;
-
-    done = findfirst(buf, &ffblk, FA_ARCH|FA_RDONLY|FA_HIDDEN|FA_DIREC);
-    if (done) {
-        PyErr_Format(PyExc_NameError,
-          "Can't find file for module %.100s\n(filename %.300s)",
-          name, buf);
-        return 0;
-    }
-    return strncmp(ffblk.ff_name, name, namelen) == 0;
-
-/* new-fangled macintosh (macosx) or Cygwin */
-#elif _POSIX_C_SOURCE || (defined(__MACH__) && defined(__APPLE__) || defined(__CYGWIN__)) && defined(HAVE_DIRENT_H)
-    DIR *dirp;
-    struct dirent *dp;
-    char dirname[MAXPATHLEN + 1];
-    const int dirlen = len - namelen - 1; /* don't want trailing SEP */
-
-    if (Py_GETENV("PYTHONCASEOK") != NULL)
-        return 1;
-
-    /* Copy the dir component into dirname; substitute "." if empty */
-    if (dirlen <= 0) {
-        dirname[0] = '.';
-        dirname[1] = '\0';
-    }
-    else {
-        assert(dirlen <= MAXPATHLEN);
-        memcpy(dirname, buf, dirlen);
-        dirname[dirlen] = '\0';
-    }
-    /* Open the directory and search the entries for an exact match. */
-    dirp = opendir(dirname);
-    if (dirp) {
-        char *nameWithExt = buf + len - namelen;
-        while ((dp = readdir(dirp)) != NULL) {
-            const int thislen =
-#ifdef _DIRENT_HAVE_D_NAMELEN
-                                    dp->d_namlen;
-#else
-                                    strlen(dp->d_name);
-#endif
-            if (thislen >= namelen &&
-                strcmp(dp->d_name, nameWithExt) == 0) {
-                (void)closedir(dirp);
-                return 1; /* Found */
-            }
-        }
-        (void)closedir(dirp);
-    }
-    return 0 ; /* Not found */
-
-/* RISC OS */
-#elif defined(RISCOS)
-    char canon[MAXPATHLEN+1]; /* buffer for the canonical form of the path */
-    char buf2[MAXPATHLEN+2];
-    char *nameWithExt = buf+len-namelen;
-    int canonlen;
-    os_error *e;
-
-    if (Py_GETENV("PYTHONCASEOK") != NULL)
-        return 1;
-
-    /* workaround:
-       append wildcard, otherwise case of filename wouldn't be touched */
-    strcpy(buf2, buf);
-    strcat(buf2, "*");
-
-    e = xosfscontrol_canonicalise_path(buf2,canon,0,0,MAXPATHLEN+1,&canonlen);
-    canonlen = MAXPATHLEN+1-canonlen;
-    if (e || canonlen<=0 || canonlen>(MAXPATHLEN+1) )
-        return 0;
-    if (strcmp(nameWithExt, canon+canonlen-strlen(nameWithExt))==0)
-        return 1; /* match */
-
-    return 0;
-
-/* OS/2 */
-#elif defined(PYOS_OS2)
-    HDIR hdir = 1;
-    ULONG srchcnt = 1;
-    FILEFINDBUF3 ffbuf;
-    APIRET rc;
-
-    if (Py_GETENV("PYTHONCASEOK") != NULL)
-        return 1;
-
-    rc = DosFindFirst(buf,
-                      &hdir,
-                      FILE_READONLY | FILE_HIDDEN | FILE_SYSTEM | FILE_DIRECTORY,
-                      &ffbuf, sizeof(ffbuf),
-                      &srchcnt,
-                      FIL_STANDARD);
-    if (rc != NO_ERROR)
-        return 0;
-    return strncmp(ffbuf.achName, name, namelen) == 0;
-
-/* assuming it's a case-sensitive filesystem, so there's nothing to do! */
-#else
-    return 1;
-
-#endif
-}
 
 
# HG changeset patch
# User Michael Witten <mfwitten@gmail.com>
# Date 1478883852 0
#      Fri Nov 11 17:04:12 2016 +0000
# Branch 2.7
# Node ID 27f45f4d72a16f70eb73d112bfc3a8e1f0285de1
# Parent  f513585d2fa120a2c14b88db3c46435c898c69c2
PEP 235: Factor out the `Py_GETENV("PYTHONCASEOK")' check

The following code is common to every platform-specific
implementation of the function `case_ok':

    if (Py_GETENV("PYTHONCASEOK") != NULL)
        return 1;

Therefore, it has been factored out of each such implementation,
and instead placed directly into the body of `case_ok'.

diff -r f513585d2fa1 -r 27f45f4d72a1 Python/import.c
--- a/Python/import.c	Sat Oct 08 19:36:36 2016 +0000
+++ b/Python/import.c	Fri Nov 11 17:04:12 2016 +0000
@@ -1672,9 +1672,6 @@
         WIN32_FIND_DATA data;
         HANDLE h;
 
-        if (Py_GETENV("PYTHONCASEOK") != NULL)
-            return 1;
-
         h = FindFirstFile(buf, &data);
         if (h == INVALID_HANDLE_VALUE) {
             PyErr_Format(PyExc_NameError,
@@ -1698,9 +1695,6 @@
         struct ffblk ffblk;
         int done;
 
-        if (Py_GETENV("PYTHONCASEOK") != NULL)
-            return 1;
-
         done = findfirst(buf, &ffblk, FA_ARCH|FA_RDONLY|FA_HIDDEN|FA_DIREC);
         if (done) {
             PyErr_Format(PyExc_NameError,
@@ -1732,9 +1726,6 @@
         char dirname[MAXPATHLEN + 1];
         const int dirlen = len - namelen - 1; /* don't want trailing SEP */
 
-        if (Py_GETENV("PYTHONCASEOK") != NULL)
-            return 1;
-
         /* Copy the dir component into dirname; substitute "." if empty */
         if (dirlen <= 0) {
             dirname[0] = '.';
@@ -1779,9 +1770,6 @@
         FILEFINDBUF3 ffbuf;
         APIRET rc;
 
-        if (Py_GETENV("PYTHONCASEOK") != NULL)
-            return 1;
-
         rc = DosFindFirst(buf,
                           &hdir,
                           FILE_READONLY | FILE_HIDDEN | FILE_SYSTEM | FILE_DIRECTORY,
@@ -1808,9 +1796,6 @@
         int canonlen;
         os_error *e;
 
-        if (Py_GETENV("PYTHONCASEOK") != NULL)
-            return 1;
-
         /* workaround:
            append wildcard, otherwise case of filename wouldn't be touched */
         strcpy(buf2, buf);
@@ -1841,6 +1826,9 @@
 static int
 case_ok(CASE_OK_PARAMS)
 {
+    if (Py_GETENV("PYTHONCASEOK") != NULL)
+        return 1;
+
     return CASE_OK_IMP(CASE_OK_ARGS);
 }