Fix handling of %TEMP% & %TMP% in tmpnam()/tmpfile()

The TEMP and TMP environment variables in DOS/Windows were not properly handled in tmpnam()/tmpfile() w.r.t. slashes in file names resulting in fallback to C:\ as the location for temporary files. While in most cases this was OK, this posed a problem for write-protected C: drives (e.g. USB sticks).
siathalysedI · Aug 10, 2016 · 0c184cd · 0c184cd
1 parent b5c3226
commit 0c184cd
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Showing 10 changed files with 28 additions and 2 deletions.
diff --git a/v0100/bind/n2f.exe b/v0100/bind/n2f.exe
diff --git a/v0100/bind/smlrcc.exe b/v0100/bind/smlrcc.exe
diff --git a/v0100/bindp/n2f.exe b/v0100/bindp/n2f.exe
diff --git a/v0100/bindp/smlrcc.exe b/v0100/bindp/smlrcc.exe
diff --git a/v0100/binw/n2f.exe b/v0100/binw/n2f.exe
diff --git a/v0100/lib/lcdh.a b/v0100/lib/lcdh.a
diff --git a/v0100/lib/lcdp.a b/v0100/lib/lcdp.a
diff --git a/v0100/lib/lcds.a b/v0100/lib/lcds.a
diff --git a/v0100/lib/lcw.a b/v0100/lib/lcw.a
diff --git a/v0100/srclib/tmpnam.c b/v0100/srclib/tmpnam.c
@@ -102,13 +102,32 @@ static
 void TryPath(char* path)
 {
   unsigned attrOrError;
+  int trailingSlash = 0;
 
   if ((plen = strlen(path)) >= L_tmpnam - (1/*slash*/ + 8+1+3/*8.3 name*/))
     return;
 
   strcpy(name, path);
-  if (name[plen - 1] != '\\' && name[plen - 1] != '/' && name[plen - 1] != ':')
-    strcat(name, "\\"), plen++;
+
+  if (name[plen - 1] == '\\' || name[plen - 1] == '/')
+    trailingSlash = name[plen - 1];
+  // The name of the directory whose existence/attribute we're about to check
+  // should end with a slash IFF it's a root directory. Valid: C:\, C:\FOO.
+  // Invalid: C:, C:\FOO\.
+  if (trailingSlash)
+  {
+    if (plen > 1 && name[plen - 2] != ':')
+      name[--plen] = '\0';
+    else
+      trailingSlash = 0;
+  }
+  else
+  {
+    if (name[plen - 1] == ':')
+      strcat(name, "\\"), plen++;
+    else
+      trailingSlash = '\\';
+  }
 
   // Check if name exists in the file system and is a directory
 #ifdef _DOS
@@ -120,6 +139,13 @@ void TryPath(char* path)
   if (attrOrError == INVALID_FILE_ATTRIBUTES || !(attrOrError & FILE_ATTRIBUTE_DIRECTORY))
     *name = '\0';
 #endif
+
+  // If it's a directory, append a slash if needed, so a file name can be appended after it
+  if (*name && trailingSlash)
+  {
+    name[plen++] = trailingSlash;
+    name[plen] = '\0';
+  }
 }
 
 static